cpython/Lib/lib2to3/fixes/fix_itertools_imports.py

46 lines
1.6 KiB
Python

""" Fixer for imports of itertools.(imap|ifilter|izip|ifilterfalse) """
# Local imports
from . import basefix
from .util import BlankLine
class FixItertoolsImports(basefix.BaseFix):
PATTERN = """
import_from< 'from' 'itertools' 'import' imports=any >
""" %(locals())
def transform(self, node, results):
imports = results['imports']
children = imports.children[:] or [imports]
for child in children:
if not hasattr(child, 'value'):
# Handle 'import ... as ...'
continue
if child.value in ('imap', 'izip', 'ifilter'):
# The value must be set to none in case child == import,
# so that the test for empty imports will work out
child.value = None
child.remove()
elif child.value == 'ifilterfalse':
node.changed()
child.value = 'filterfalse'
# Make sure the import statement is still sane
children = imports.children[:] or [imports]
remove_comma = True
for child in children:
if remove_comma and getattr(child, 'value', None) == ',':
child.remove()
else:
remove_comma ^= True
if str(children[-1]) == ',':
children[-1].remove()
# If there are no imports left, just get rid of the entire statement
if not (imports.children or getattr(imports, 'value', None)):
p = node.get_prefix()
node = BlankLine()
node.prefix = p
return node