594 lines
22 KiB
Python
594 lines
22 KiB
Python
# Copyright 2006 Google, Inc. All Rights Reserved.
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# Licensed to PSF under a Contributor Agreement.
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"""Refactoring framework.
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Used as a main program, this can refactor any number of files and/or
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recursively descend down directories. Imported as a module, this
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provides infrastructure to write your own refactoring tool.
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"""
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__author__ = "Guido van Rossum <guido@python.org>"
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# Python imports
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import os
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import sys
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import difflib
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import logging
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import operator
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from collections import defaultdict
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from itertools import chain
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# Local imports
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from .pgen2 import driver, tokenize
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from . import pytree, pygram
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def get_all_fix_names(fixer_pkg, remove_prefix=True):
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"""Return a sorted list of all available fix names in the given package."""
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pkg = __import__(fixer_pkg, [], [], ["*"])
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fixer_dir = os.path.dirname(pkg.__file__)
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fix_names = []
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for name in sorted(os.listdir(fixer_dir)):
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if name.startswith("fix_") and name.endswith(".py"):
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if remove_prefix:
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name = name[4:]
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fix_names.append(name[:-3])
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return fix_names
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def get_head_types(pat):
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""" Accepts a pytree Pattern Node and returns a set
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of the pattern types which will match first. """
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if isinstance(pat, (pytree.NodePattern, pytree.LeafPattern)):
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# NodePatters must either have no type and no content
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# or a type and content -- so they don't get any farther
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# Always return leafs
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return set([pat.type])
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if isinstance(pat, pytree.NegatedPattern):
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if pat.content:
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return get_head_types(pat.content)
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return set([None]) # Negated Patterns don't have a type
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if isinstance(pat, pytree.WildcardPattern):
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# Recurse on each node in content
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r = set()
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for p in pat.content:
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for x in p:
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r.update(get_head_types(x))
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return r
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raise Exception("Oh no! I don't understand pattern %s" %(pat))
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def get_headnode_dict(fixer_list):
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""" Accepts a list of fixers and returns a dictionary
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of head node type --> fixer list. """
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head_nodes = defaultdict(list)
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for fixer in fixer_list:
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if not fixer.pattern:
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head_nodes[None].append(fixer)
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continue
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for t in get_head_types(fixer.pattern):
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head_nodes[t].append(fixer)
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return head_nodes
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def get_fixers_from_package(pkg_name):
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"""
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Return the fully qualified names for fixers in the package pkg_name.
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"""
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return [pkg_name + "." + fix_name
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for fix_name in get_all_fix_names(pkg_name, False)]
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def _identity(obj):
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return obj
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if sys.version_info < (3, 0):
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import codecs
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_open_with_encoding = codecs.open
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# codecs.open doesn't translate newlines sadly.
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def _from_system_newlines(input):
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return input.replace("\r\n", "\n")
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def _to_system_newlines(input):
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if os.linesep != "\n":
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return input.replace("\n", os.linesep)
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else:
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return input
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else:
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_open_with_encoding = open
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_from_system_newlines = _identity
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_to_system_newlines = _identity
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class FixerError(Exception):
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"""A fixer could not be loaded."""
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class RefactoringTool(object):
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_default_options = {"print_function": False}
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CLASS_PREFIX = "Fix" # The prefix for fixer classes
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FILE_PREFIX = "fix_" # The prefix for modules with a fixer within
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def __init__(self, fixer_names, options=None, explicit=None):
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"""Initializer.
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Args:
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fixer_names: a list of fixers to import
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options: an dict with configuration.
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explicit: a list of fixers to run even if they are explicit.
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"""
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self.fixers = fixer_names
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self.explicit = explicit or []
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self.options = self._default_options.copy()
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if options is not None:
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self.options.update(options)
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self.errors = []
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self.logger = logging.getLogger("RefactoringTool")
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self.fixer_log = []
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self.wrote = False
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if self.options["print_function"]:
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del pygram.python_grammar.keywords["print"]
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self.driver = driver.Driver(pygram.python_grammar,
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convert=pytree.convert,
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logger=self.logger)
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self.pre_order, self.post_order = self.get_fixers()
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self.pre_order_heads = get_headnode_dict(self.pre_order)
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self.post_order_heads = get_headnode_dict(self.post_order)
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self.files = [] # List of files that were or should be modified
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def get_fixers(self):
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"""Inspects the options to load the requested patterns and handlers.
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Returns:
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(pre_order, post_order), where pre_order is the list of fixers that
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want a pre-order AST traversal, and post_order is the list that want
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post-order traversal.
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"""
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pre_order_fixers = []
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post_order_fixers = []
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for fix_mod_path in self.fixers:
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mod = __import__(fix_mod_path, {}, {}, ["*"])
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fix_name = fix_mod_path.rsplit(".", 1)[-1]
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if fix_name.startswith(self.FILE_PREFIX):
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fix_name = fix_name[len(self.FILE_PREFIX):]
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parts = fix_name.split("_")
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class_name = self.CLASS_PREFIX + "".join([p.title() for p in parts])
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try:
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fix_class = getattr(mod, class_name)
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except AttributeError:
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raise FixerError("Can't find %s.%s" % (fix_name, class_name))
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fixer = fix_class(self.options, self.fixer_log)
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if fixer.explicit and self.explicit is not True and \
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fix_mod_path not in self.explicit:
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self.log_message("Skipping implicit fixer: %s", fix_name)
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continue
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self.log_debug("Adding transformation: %s", fix_name)
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if fixer.order == "pre":
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pre_order_fixers.append(fixer)
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elif fixer.order == "post":
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post_order_fixers.append(fixer)
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else:
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raise FixerError("Illegal fixer order: %r" % fixer.order)
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key_func = operator.attrgetter("run_order")
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pre_order_fixers.sort(key=key_func)
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post_order_fixers.sort(key=key_func)
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return (pre_order_fixers, post_order_fixers)
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def log_error(self, msg, *args, **kwds):
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"""Called when an error occurs."""
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raise
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def log_message(self, msg, *args):
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"""Hook to log a message."""
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if args:
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msg = msg % args
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self.logger.info(msg)
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def log_debug(self, msg, *args):
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if args:
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msg = msg % args
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self.logger.debug(msg)
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def print_output(self, lines):
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"""Called with lines of output to give to the user."""
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pass
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def refactor(self, items, write=False, doctests_only=False):
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"""Refactor a list of files and directories."""
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for dir_or_file in items:
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if os.path.isdir(dir_or_file):
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self.refactor_dir(dir_or_file, write, doctests_only)
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else:
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self.refactor_file(dir_or_file, write, doctests_only)
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def refactor_dir(self, dir_name, write=False, doctests_only=False):
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"""Descends down a directory and refactor every Python file found.
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Python files are assumed to have a .py extension.
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Files and subdirectories starting with '.' are skipped.
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"""
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for dirpath, dirnames, filenames in os.walk(dir_name):
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self.log_debug("Descending into %s", dirpath)
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dirnames.sort()
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filenames.sort()
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for name in filenames:
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if not name.startswith(".") and name.endswith("py"):
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fullname = os.path.join(dirpath, name)
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self.refactor_file(fullname, write, doctests_only)
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# Modify dirnames in-place to remove subdirs with leading dots
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dirnames[:] = [dn for dn in dirnames if not dn.startswith(".")]
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def _read_python_source(self, filename):
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"""
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Do our best to decode a Python source file correctly.
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"""
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try:
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f = open(filename, "rb")
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except IOError as err:
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self.log_error("Can't open %s: %s", filename, err)
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return None, None
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try:
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encoding = tokenize.detect_encoding(f.readline)[0]
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finally:
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f.close()
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with _open_with_encoding(filename, "r", encoding=encoding) as f:
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return _from_system_newlines(f.read()), encoding
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def refactor_file(self, filename, write=False, doctests_only=False):
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"""Refactors a file."""
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input, encoding = self._read_python_source(filename)
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if input is None:
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# Reading the file failed.
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return
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input += "\n" # Silence certain parse errors
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if doctests_only:
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self.log_debug("Refactoring doctests in %s", filename)
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output = self.refactor_docstring(input, filename)
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if output != input:
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self.processed_file(output, filename, input, write, encoding)
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else:
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self.log_debug("No doctest changes in %s", filename)
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else:
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tree = self.refactor_string(input, filename)
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if tree and tree.was_changed:
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# The [:-1] is to take off the \n we added earlier
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self.processed_file(str(tree)[:-1], filename,
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write=write, encoding=encoding)
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else:
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self.log_debug("No changes in %s", filename)
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def refactor_string(self, data, name):
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"""Refactor a given input string.
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Args:
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data: a string holding the code to be refactored.
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name: a human-readable name for use in error/log messages.
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Returns:
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An AST corresponding to the refactored input stream; None if
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there were errors during the parse.
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"""
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try:
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tree = self.driver.parse_string(data)
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except Exception as err:
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self.log_error("Can't parse %s: %s: %s",
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name, err.__class__.__name__, err)
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return
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self.log_debug("Refactoring %s", name)
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self.refactor_tree(tree, name)
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return tree
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def refactor_stdin(self, doctests_only=False):
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input = sys.stdin.read()
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if doctests_only:
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self.log_debug("Refactoring doctests in stdin")
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output = self.refactor_docstring(input, "<stdin>")
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if output != input:
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self.processed_file(output, "<stdin>", input)
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else:
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self.log_debug("No doctest changes in stdin")
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else:
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tree = self.refactor_string(input, "<stdin>")
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if tree and tree.was_changed:
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self.processed_file(str(tree), "<stdin>", input)
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else:
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self.log_debug("No changes in stdin")
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def refactor_tree(self, tree, name):
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"""Refactors a parse tree (modifying the tree in place).
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Args:
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tree: a pytree.Node instance representing the root of the tree
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to be refactored.
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name: a human-readable name for this tree.
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Returns:
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True if the tree was modified, False otherwise.
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"""
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for fixer in chain(self.pre_order, self.post_order):
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fixer.start_tree(tree, name)
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self.traverse_by(self.pre_order_heads, tree.pre_order())
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self.traverse_by(self.post_order_heads, tree.post_order())
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for fixer in chain(self.pre_order, self.post_order):
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fixer.finish_tree(tree, name)
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return tree.was_changed
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def traverse_by(self, fixers, traversal):
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"""Traverse an AST, applying a set of fixers to each node.
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This is a helper method for refactor_tree().
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Args:
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fixers: a list of fixer instances.
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traversal: a generator that yields AST nodes.
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Returns:
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None
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"""
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if not fixers:
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return
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for node in traversal:
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for fixer in fixers[node.type] + fixers[None]:
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results = fixer.match(node)
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if results:
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new = fixer.transform(node, results)
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if new is not None and (new != node or
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str(new) != str(node)):
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node.replace(new)
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node = new
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def processed_file(self, new_text, filename, old_text=None, write=False,
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encoding=None):
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"""
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Called when a file has been refactored, and there are changes.
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"""
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self.files.append(filename)
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if old_text is None:
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old_text = self._read_python_source(filename)[0]
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if old_text is None:
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return
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if old_text == new_text:
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self.log_debug("No changes to %s", filename)
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return
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self.print_output(diff_texts(old_text, new_text, filename))
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if write:
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self.write_file(new_text, filename, old_text, encoding)
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else:
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self.log_debug("Not writing changes to %s", filename)
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def write_file(self, new_text, filename, old_text, encoding=None):
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"""Writes a string to a file.
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It first shows a unified diff between the old text and the new text, and
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then rewrites the file; the latter is only done if the write option is
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set.
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"""
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try:
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f = _open_with_encoding(filename, "w", encoding=encoding)
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except os.error as err:
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self.log_error("Can't create %s: %s", filename, err)
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return
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try:
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f.write(_to_system_newlines(new_text))
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except os.error as err:
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self.log_error("Can't write %s: %s", filename, err)
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finally:
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f.close()
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self.log_debug("Wrote changes to %s", filename)
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self.wrote = True
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PS1 = ">>> "
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PS2 = "... "
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def refactor_docstring(self, input, filename):
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"""Refactors a docstring, looking for doctests.
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This returns a modified version of the input string. It looks
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for doctests, which start with a ">>>" prompt, and may be
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continued with "..." prompts, as long as the "..." is indented
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the same as the ">>>".
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(Unfortunately we can't use the doctest module's parser,
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since, like most parsers, it is not geared towards preserving
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the original source.)
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"""
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result = []
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block = None
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block_lineno = None
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indent = None
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lineno = 0
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for line in input.splitlines(True):
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lineno += 1
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if line.lstrip().startswith(self.PS1):
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if block is not None:
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result.extend(self.refactor_doctest(block, block_lineno,
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indent, filename))
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block_lineno = lineno
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block = [line]
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i = line.find(self.PS1)
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indent = line[:i]
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elif (indent is not None and
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(line.startswith(indent + self.PS2) or
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line == indent + self.PS2.rstrip() + "\n")):
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block.append(line)
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else:
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if block is not None:
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result.extend(self.refactor_doctest(block, block_lineno,
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indent, filename))
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block = None
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indent = None
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result.append(line)
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if block is not None:
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result.extend(self.refactor_doctest(block, block_lineno,
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indent, filename))
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return "".join(result)
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def refactor_doctest(self, block, lineno, indent, filename):
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"""Refactors one doctest.
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A doctest is given as a block of lines, the first of which starts
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with ">>>" (possibly indented), while the remaining lines start
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with "..." (identically indented).
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"""
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try:
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tree = self.parse_block(block, lineno, indent)
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except Exception as err:
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if self.log.isEnabledFor(logging.DEBUG):
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for line in block:
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self.log_debug("Source: %s", line.rstrip("\n"))
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self.log_error("Can't parse docstring in %s line %s: %s: %s",
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filename, lineno, err.__class__.__name__, err)
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return block
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if self.refactor_tree(tree, filename):
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new = str(tree).splitlines(True)
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# Undo the adjustment of the line numbers in wrap_toks() below.
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clipped, new = new[:lineno-1], new[lineno-1:]
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assert clipped == ["\n"] * (lineno-1), clipped
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if not new[-1].endswith("\n"):
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new[-1] += "\n"
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block = [indent + self.PS1 + new.pop(0)]
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if new:
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block += [indent + self.PS2 + line for line in new]
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return block
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def summarize(self):
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if self.wrote:
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were = "were"
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else:
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were = "need to be"
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if not self.files:
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self.log_message("No files %s modified.", were)
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else:
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self.log_message("Files that %s modified:", were)
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for file in self.files:
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self.log_message(file)
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if self.fixer_log:
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self.log_message("Warnings/messages while refactoring:")
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for message in self.fixer_log:
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self.log_message(message)
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if self.errors:
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if len(self.errors) == 1:
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self.log_message("There was 1 error:")
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else:
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self.log_message("There were %d errors:", len(self.errors))
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for msg, args, kwds in self.errors:
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self.log_message(msg, *args, **kwds)
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def parse_block(self, block, lineno, indent):
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"""Parses a block into a tree.
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This is necessary to get correct line number / offset information
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in the parser diagnostics and embedded into the parse tree.
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"""
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return self.driver.parse_tokens(self.wrap_toks(block, lineno, indent))
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def wrap_toks(self, block, lineno, indent):
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"""Wraps a tokenize stream to systematically modify start/end."""
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tokens = tokenize.generate_tokens(self.gen_lines(block, indent).__next__)
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for type, value, (line0, col0), (line1, col1), line_text in tokens:
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line0 += lineno - 1
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line1 += lineno - 1
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# Don't bother updating the columns; this is too complicated
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# since line_text would also have to be updated and it would
|
|
# still break for tokens spanning lines. Let the user guess
|
|
# that the column numbers for doctests are relative to the
|
|
# end of the prompt string (PS1 or PS2).
|
|
yield type, value, (line0, col0), (line1, col1), line_text
|
|
|
|
|
|
def gen_lines(self, block, indent):
|
|
"""Generates lines as expected by tokenize from a list of lines.
|
|
|
|
This strips the first len(indent + self.PS1) characters off each line.
|
|
"""
|
|
prefix1 = indent + self.PS1
|
|
prefix2 = indent + self.PS2
|
|
prefix = prefix1
|
|
for line in block:
|
|
if line.startswith(prefix):
|
|
yield line[len(prefix):]
|
|
elif line == prefix.rstrip() + "\n":
|
|
yield "\n"
|
|
else:
|
|
raise AssertionError("line=%r, prefix=%r" % (line, prefix))
|
|
prefix = prefix2
|
|
while True:
|
|
yield ""
|
|
|
|
|
|
class MultiprocessingUnsupported(Exception):
|
|
pass
|
|
|
|
|
|
class MultiprocessRefactoringTool(RefactoringTool):
|
|
|
|
def __init__(self, *args, **kwargs):
|
|
super(MultiprocessRefactoringTool, self).__init__(*args, **kwargs)
|
|
self.queue = None
|
|
|
|
def refactor(self, items, write=False, doctests_only=False,
|
|
num_processes=1):
|
|
if num_processes == 1:
|
|
return super(MultiprocessRefactoringTool, self).refactor(
|
|
items, write, doctests_only)
|
|
try:
|
|
import multiprocessing
|
|
except ImportError:
|
|
raise MultiprocessingUnsupported
|
|
if self.queue is not None:
|
|
raise RuntimeError("already doing multiple processes")
|
|
self.queue = multiprocessing.JoinableQueue()
|
|
processes = [multiprocessing.Process(target=self._child)
|
|
for i in range(num_processes)]
|
|
try:
|
|
for p in processes:
|
|
p.start()
|
|
super(MultiprocessRefactoringTool, self).refactor(items, write,
|
|
doctests_only)
|
|
finally:
|
|
self.queue.join()
|
|
for i in range(num_processes):
|
|
self.queue.put(None)
|
|
for p in processes:
|
|
if p.is_alive():
|
|
p.join()
|
|
self.queue = None
|
|
|
|
def _child(self):
|
|
task = self.queue.get()
|
|
while task is not None:
|
|
args, kwargs = task
|
|
try:
|
|
super(MultiprocessRefactoringTool, self).refactor_file(
|
|
*args, **kwargs)
|
|
finally:
|
|
self.queue.task_done()
|
|
task = self.queue.get()
|
|
|
|
def refactor_file(self, *args, **kwargs):
|
|
if self.queue is not None:
|
|
self.queue.put((args, kwargs))
|
|
else:
|
|
return super(MultiprocessRefactoringTool, self).refactor_file(
|
|
*args, **kwargs)
|
|
|
|
|
|
def diff_texts(a, b, filename):
|
|
"""Return a unified diff of two strings."""
|
|
a = a.splitlines()
|
|
b = b.splitlines()
|
|
return difflib.unified_diff(a, b, filename, filename,
|
|
"(original)", "(refactored)",
|
|
lineterm="")
|