mirror of https://github.com/python/cpython
UserString class from Peter Funk <pf@artcom-gmbh.de>.
This commit is contained in:
Fred Drake
parent
e3ba931aa4
commit
a22b576d05
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@ -63,3 +63,52 @@ provide the following attribute:
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A real Python list object used to store the contents of the
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\class{UserList} class.
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\end{memberdesc}
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\section{\module{UserString} ---
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Class wrapper for string objects}
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\declaremodule{standard}{UserString}
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\modulesynopsis{Class wrapper for string objects.}
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\moduleauthor{Peter Funk}{pf@artcom-gmbh.de}
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\sectionauthor{Peter Funk}{pf@artcom-gmbh.de}
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This module defines a class that acts as a wrapper around
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string objects. It is a useful base class for
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your own string-like classes, which can inherit from
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them and override existing methods or add new ones. In this way one
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can add new behaviours to strings.
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The \module{UserString} module defines the \class{UserString} class:
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\begin{classdesc}{UserString}{\optional{sequence}}
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Return a class instance that simulates a string or an unicode string object.
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The instance's content is kept in a regular string or unicode string
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object, which is accessible via the
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\member{data} attribute of \class{UserString} instances. The instance's
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contents are initially set to a copy of \var{sequence}.
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\var{sequence} can be either a regular Python string or unicode string,
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an instance of \class{UserString} (or a subclass) or an arbitrary sequence
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which can be converted into a string.
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supporting.
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\end{classdesc}
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In addition to supporting the methods and operations of string or
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unicode objects (see section \ref{typesseq}), \class{UserString} instances
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provide the following attribute:
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\begin{memberdesc}{data}
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A real Python string or unicode object used to store the content of the
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\class{UserString} class.
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\end{memberdesc}
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\begin{classdesc}{MutableString}{\optional{sequence}}
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This class is derived from the \class{UserString} above and redefines
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strings to be \emph{mutable}. Mutable strings can't be used as
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dictionary keys, because dictionaries require \emph{immutable} objects as
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keys. The main intention of this class is to serve as an educational
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example for inheritance and necessity to remove (override) the
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\function{__hash__} method in order to trap attempts to use a
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mutable object as dictionary key, which would be otherwise very
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errorprone and hard to track down.
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\end{classdesc}
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@ -0,0 +1,158 @@
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#!/usr/bin/env python
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## vim:ts=4:et:nowrap
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"""A user-defined wrapper around string objects
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Note: string objects have grown methods in Python 1.6
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This module requires Python 1.6 or later.
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"""
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from types import StringType, UnicodeType
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import sys
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class UserString:
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def __init__(self, seq):
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if isinstance(seq, StringType) or isinstance(seq, UnicodeType):
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self.data = seq
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elif isinstance(seq, UserString):
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self.data = seq.data[:]
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else:
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self.data = str(seq)
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def __str__(self): return str(self.data)
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def __repr__(self): return repr(self.data)
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def __int__(self): return int(self.data)
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def __long__(self): return long(self.data)
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def __float__(self): return float(self.data)
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def __complex__(self): return complex(self.data)
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def __hash__(self): return hash(self.data)
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def __cmp__(self, string):
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if isinstance(string, UserString):
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return cmp(self.data, string.data)
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else:
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return cmp(self.data, string)
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def __contains__(self, char):
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return char in self.data
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def __len__(self): return len(self.data)
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def __getitem__(self, index): return self.__class__(self.data[index])
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def __getslice__(self, start, end):
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start = max(start, 0); end = max(end, 0)
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return self.__class__(self.data[start:end])
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def __add__(self, other):
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if isinstance(other, UserString):
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return self.__class__(self.data + other.data)
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elif isinstance(other, StringType) or isinstance(other, UnicodeType):
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return self.__class__(self.data + other)
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else:
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return self.__class__(self.data + str(other))
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def __radd__(self, other):
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if isinstance(other, StringType) or isinstance(other, UnicodeType):
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return self.__class__(other + self.data)
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else:
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return self.__class__(str(other) + self.data)
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def __mul__(self, n):
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return self.__class__(self.data*n)
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__rmul__ = __mul__
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# the following methods are defined in alphabetical order:
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def capitalize(self): return self.__class__(self.data.capitalize())
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def center(self, width): return self.__class__(self.data.center(width))
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def count(self, sub, start=0, end=sys.maxint):
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return self.data.count(sub, start, end)
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def encode(self, encoding=None, errors=None): # XXX improve this?
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if encoding:
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if errors:
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return self.__class__(self.data.encode(encoding, errors))
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else:
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return self.__class__(self.data.encode(encoding))
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else:
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return self.__class__(self.data.encode())
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def endswith(self, suffix, start=0, end=sys.maxint):
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return self.data.endswith(suffix, start, end)
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def expandtabs(self, tabsize=8):
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return self.__class__(self.data.expandtabs(tabsize))
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def find(self, sub, start=0, end=sys.maxint):
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return self.data.find(sub, start, end)
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def index(self, sub, start=0, end=sys.maxint):
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return self.data.index(sub, start, end)
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def isdecimal(self): return self.data.isdecimal()
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def isdigit(self): return self.data.isdigit()
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def islower(self): return self.data.islower()
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def isnumeric(self): return self.data.isnumeric()
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def isspace(self): return self.data.isspace()
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def istitle(self): return self.data.istitle()
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def isupper(self): return self.data.isupper()
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def join(self, seq): return self.data.join(seq)
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def ljust(self, width): return self.__class__(self.data.ljust(width))
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def lower(self): return self.__class__(self.data.lower())
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def lstrip(self): return self.__class__(self.data.lstrip())
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def replace(self, old, new, maxsplit=-1):
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return self.__class__(self.data.replace(old, new, maxsplit))
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def rfind(self, sub, start=0, end=sys.maxint):
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return self.data.rfind(sub, start, end)
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def rindex(self, sub, start=0, end=sys.maxint):
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return self.data.rindex(sub, start, end)
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def rjust(self, width): return self.__class__(self.data.rjust(width))
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def rstrip(self): return self.__class__(self.data.rstrip())
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def split(self, sep=None, maxsplit=-1):
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return self.data.split(sep, maxsplit)
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def splitlines(self, maxsplit=-1): return self.data.splitlines(maxsplit)
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def startswith(self, prefix, start=0, end=sys.maxint):
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return self.data.startswith(prefix, start, end)
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def strip(self): return self.__class__(self.data.strip())
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def swapcase(self): return self.__class__(self.data.swapcase())
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def title(self): return self.__class__(self.data.title())
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def translate(self, table, deletechars=""):
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return self.__class__(self.data.translate(table, deletechars))
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def upper(self): return self.__class__(self.data.upper())
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class MutableString(UserString):
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"""mutable string objects
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Python strings are immutable objects. This has the advantage, that
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strings may be used as dictionary keys. If this property isn't needed
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and you insist on changing string values in place instead, you may cheat
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and use MutableString.
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But the purpose of this class is an educational one: to prevent
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people from inventing their own mutable string class derived
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from UserString and than forget thereby to remove (override) the
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__hash__ method inherited from ^UserString. This would lead to
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errors that would be very hard to track down.
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A faster and better solution is to rewrite your program using lists."""
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def __init__(self, string=""):
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self.data = string
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def __hash__(self):
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raise TypeError, "unhashable type (it is mutable)"
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def __setitem__(self, index, sub):
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if index < 0 or index >= len(self.data): raise IndexError
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self.data = self.data[:index] + sub + self.data[index+1:]
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def __delitem__(self, index):
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if index < 0 or index >= len(self.data): raise IndexError
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self.data = self.data[:index] + self.data[index+1:]
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def __setslice__(self, start, end, sub):
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start = max(start, 0); end = max(end, 0)
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if isinstance(sub, UserString):
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self.data = self.data[:start]+sub.data+self.data[end:]
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elif isinstance(sub, StringType) or isinstance(sub, UnicodeType):
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self.data = self.data[:start]+sub+self.data[end:]
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else:
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self.data = self.data[:start]+str(sub)+self.data[end:]
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def __delslice__(self, start, end):
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start = max(start, 0); end = max(end, 0)
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self.data = self.data[:start] + self.data[end:]
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def immutable(self):
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return UserString(self.data)
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if __name__ == "__main__":
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# execute the regression test to stdout, if called as a script:
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import os
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called_in_dir, called_as = os.path.split(sys.argv[0])
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called_in_dir = os.path.abspath(called_in_dir)
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called_as, py = os.path.splitext(called_as)
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sys.path.append(os.path.join(called_in_dir, 'test'))
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if '-q' in sys.argv:
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import test_support
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test_support.verbose = 0
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__import__('test_' + called_as.lower())
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@ -0,0 +1 @@
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test_userstring
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@ -0,0 +1,227 @@
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#!/usr/bin/env python
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import sys, string
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from test_support import verbose
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# UserString is a wrapper around the native builtin string type.
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# UserString instances should behave similar to builtin string objects.
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# The test cases were in part derived from 'test_string.py'.
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from UserString import UserString
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if __name__ == "__main__":
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verbose = 0
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tested_methods = {}
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def test(methodname, input, *args):
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global tested_methods
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tested_methods[methodname] = 1
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if verbose:
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print '%s.%s(%s) ' % (input, methodname, args),
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u = UserString(input)
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objects = [input, u, UserString(u)]
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res = [""] * 3
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for i in range(3):
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object = objects[i]
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try:
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f = getattr(object, methodname)
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res[i] = apply(f, args)
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except:
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res[i] = sys.exc_type
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if res[0] != res[1]:
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if verbose:
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print 'no'
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print `input`, f, `res[0]`, "<>", `res[1]`
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else:
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if verbose:
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print 'yes'
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if res[1] != res[2]:
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if verbose:
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print 'no'
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print `input`, f, `res[1]`, "<>", `res[2]`
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else:
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if verbose:
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print 'yes'
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test('capitalize', ' hello ')
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test('capitalize', 'hello ')
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test('center', 'foo', 0)
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test('center', 'foo', 3)
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test('center', 'foo', 16)
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test('ljust', 'foo', 0)
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test('ljust', 'foo', 3)
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test('ljust', 'foo', 16)
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test('rjust', 'foo', 0)
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test('rjust', 'foo', 3)
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test('rjust', 'foo', 16)
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test('count', 'abcabcabc', 'abc')
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test('count', 'abcabcabc', 'abc', 1)
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test('count', 'abcabcabc', 'abc', -1)
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test('count', 'abcabcabc', 'abc', 7)
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test('count', 'abcabcabc', 'abc', 0, 3)
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test('count', 'abcabcabc', 'abc', 0, 333)
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test('find', 'abcdefghiabc', 'abc')
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test('find', 'abcdefghiabc', 'abc', 1)
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test('find', 'abcdefghiabc', 'def', 4)
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test('rfind', 'abcdefghiabc', 'abc')
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test('index', 'abcabcabc', 'abc')
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test('index', 'abcabcabc', 'abc', 1)
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test('index', 'abcabcabc', 'abc', -1)
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test('index', 'abcabcabc', 'abc', 7)
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test('index', 'abcabcabc', 'abc', 0, 3)
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test('index', 'abcabcabc', 'abc', 0, 333)
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test('rindex', 'abcabcabc', 'abc')
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test('rindex', 'abcabcabc', 'abc', 1)
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test('rindex', 'abcabcabc', 'abc', -1)
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test('rindex', 'abcabcabc', 'abc', 7)
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test('rindex', 'abcabcabc', 'abc', 0, 3)
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test('rindex', 'abcabcabc', 'abc', 0, 333)
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test('lower', 'HeLLo')
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test('lower', 'hello')
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test('upper', 'HeLLo')
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test('upper', 'HELLO')
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test('title', ' hello ')
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test('title', 'hello ')
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test('title', "fOrMaT thIs aS titLe String")
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test('title', "fOrMaT,thIs-aS*titLe;String")
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test('title', "getInt")
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test('expandtabs', 'abc\rab\tdef\ng\thi')
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test('expandtabs', 'abc\rab\tdef\ng\thi', 8)
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test('expandtabs', 'abc\rab\tdef\ng\thi', 4)
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test('expandtabs', 'abc\r\nab\tdef\ng\thi', 4)
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test('islower', 'a')
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test('islower', 'A')
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test('islower', '\n')
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test('islower', 'abc')
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test('islower', 'aBc')
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test('islower', 'abc\n')
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test('isupper', 'a')
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test('isupper', 'A')
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test('isupper', '\n')
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test('isupper', 'ABC')
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test('isupper', 'AbC')
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test('isupper', 'ABC\n')
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test('isdigit', ' 0123456789')
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test('isdigit', '56789')
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test('isdigit', '567.89')
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test('isdigit', '0123456789abc')
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test('isspace', '')
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test('isspace', ' ')
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test('isspace', ' \t')
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test('isspace', ' \t\f\n')
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test('istitle', 'a')
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test('istitle', 'A')
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test('istitle', '\n')
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test('istitle', 'A Titlecased Line')
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test('istitle', 'A\nTitlecased Line')
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test('istitle', 'A Titlecased, Line')
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test('istitle', 'Not a capitalized String')
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test('istitle', 'Not\ta Titlecase String')
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test('istitle', 'Not--a Titlecase String')
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test('splitlines', "abc\ndef\n\rghi")
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test('splitlines', "abc\ndef\n\r\nghi")
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test('splitlines', "abc\ndef\r\nghi")
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test('splitlines', "abc\ndef\r\nghi\n")
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test('splitlines', "abc\ndef\r\nghi\n\r")
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test('splitlines', "\nabc\ndef\r\nghi\n\r")
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test('splitlines', "\nabc\ndef\r\nghi\n\r")
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test('splitlines', "\nabc\ndef\r\nghi\n\r")
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test('split', 'this is the split function')
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test('split', 'a|b|c|d', '|')
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test('split', 'a|b|c|d', '|', 2)
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test('split', 'a b c d', None, 1)
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test('split', 'a b c d', None, 2)
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test('split', 'a b c d', None, 3)
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test('split', 'a b c d', None, 4)
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test('split', 'a b c d', None, 0)
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test('split', 'a b c d', None, 2)
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test('split', 'a b c d ')
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# join now works with any sequence type
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class Sequence:
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def __init__(self): self.seq = 'wxyz'
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def __len__(self): return len(self.seq)
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def __getitem__(self, i): return self.seq[i]
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test('join', '', ('a', 'b', 'c', 'd'))
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test('join', '', Sequence())
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test('join', '', 7)
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class BadSeq(Sequence):
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def __init__(self): self.seq = [7, 'hello', 123L]
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test('join', '', BadSeq())
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test('strip', ' hello ')
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test('lstrip', ' hello ')
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test('rstrip', ' hello ')
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test('strip', 'hello')
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test('swapcase', 'HeLLo cOmpUteRs')
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transtable = string.maketrans("abc", "xyz")
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test('translate', 'xyzabcdef', transtable, 'def')
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transtable = string.maketrans('a', 'A')
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test('translate', 'abc', transtable)
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test('translate', 'xyz', transtable)
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test('replace', 'one!two!three!', '!', '@', 1)
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test('replace', 'one!two!three!', '!', '')
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test('replace', 'one!two!three!', '!', '@', 2)
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test('replace', 'one!two!three!', '!', '@', 3)
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test('replace', 'one!two!three!', '!', '@', 4)
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test('replace', 'one!two!three!', '!', '@', 0)
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test('replace', 'one!two!three!', '!', '@')
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test('replace', 'one!two!three!', 'x', '@')
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test('replace', 'one!two!three!', 'x', '@', 2)
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test('startswith', 'hello', 'he')
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test('startswith', 'hello', 'hello')
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test('startswith', 'hello', 'hello world')
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test('startswith', 'hello', '')
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test('startswith', 'hello', 'ello')
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test('startswith', 'hello', 'ello', 1)
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test('startswith', 'hello', 'o', 4)
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test('startswith', 'hello', 'o', 5)
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test('startswith', 'hello', '', 5)
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test('startswith', 'hello', 'lo', 6)
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test('startswith', 'helloworld', 'lowo', 3)
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test('startswith', 'helloworld', 'lowo', 3, 7)
|
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test('startswith', 'helloworld', 'lowo', 3, 6)
|
||||
|
||||
test('endswith', 'hello', 'lo')
|
||||
test('endswith', 'hello', 'he')
|
||||
test('endswith', 'hello', '')
|
||||
test('endswith', 'hello', 'hello world')
|
||||
test('endswith', 'helloworld', 'worl')
|
||||
test('endswith', 'helloworld', 'worl', 3, 9)
|
||||
test('endswith', 'helloworld', 'world', 3, 12)
|
||||
test('endswith', 'helloworld', 'lowo', 1, 7)
|
||||
test('endswith', 'helloworld', 'lowo', 2, 7)
|
||||
test('endswith', 'helloworld', 'lowo', 3, 7)
|
||||
test('endswith', 'helloworld', 'lowo', 4, 7)
|
||||
test('endswith', 'helloworld', 'lowo', 3, 8)
|
||||
test('endswith', 'ab', 'ab', 0, 1)
|
||||
test('endswith', 'ab', 'ab', 0, 0)
|
||||
|
||||
# TODO: test cases for: int, long, float, complex, +, * and cmp
|
||||
s = ""
|
||||
for builtin_method in dir(s):
|
||||
if not tested_methods.has_key(builtin_method):
|
||||
print "no regression test case for method '"+builtin_method+"'"
|
||||
Loading…
Reference in New Issue