Lib/dos-8x3/userstri.py

   1 #!/usr/bin/env python
   2 ## vim:ts=4:et:nowrap
   3 """A user-defined wrapper around string objects
   4
   5 Note: string objects have grown methods in Python 1.6
   6 This module requires Python 1.6 or later.
   7 """
   8 from types import StringType, UnicodeType
   9 import sys
  10
  11 class UserString:
  12     def __init__(self, seq):
  13         if isinstance(seq, StringType) or isinstance(seq, UnicodeType):
  14             self.data = seq
  15         elif isinstance(seq, UserString):
  16             self.data = seq.data[:]
  17         else:
  18             self.data = str(seq)
  19     def __str__(self): return str(self.data)
  20     def __repr__(self): return repr(self.data)
  21     def __int__(self): return int(self.data)
  22     def __long__(self): return long(self.data)
  23     def __float__(self): return float(self.data)
  24     def __complex__(self): return complex(self.data)
  25     def __hash__(self): return hash(self.data)
  26
  27     def __cmp__(self, string):
  28         if isinstance(string, UserString):
  29             return cmp(self.data, string.data)
  30         else:
  31             return cmp(self.data, string)
  32     def __contains__(self, char):
  33         return char in self.data
  34
  35     def __len__(self): return len(self.data)
  36     def __getitem__(self, index): return self.__class__(self.data[index])
  37     def __getslice__(self, start, end):
  38         start = max(start, 0); end = max(end, 0)
  39         return self.__class__(self.data[start:end])
  40
  41     def __add__(self, other):
  42         if isinstance(other, UserString):
  43             return self.__class__(self.data + other.data)
  44         elif isinstance(other, StringType) or isinstance(other, UnicodeType):
  45             return self.__class__(self.data + other)
  46         else:
  47             return self.__class__(self.data + str(other))
  48     def __radd__(self, other):
  49         if isinstance(other, StringType) or isinstance(other, UnicodeType):
  50             return self.__class__(other + self.data)
  51         else:
  52             return self.__class__(str(other) + self.data)
  53     def __mul__(self, n):
  54         return self.__class__(self.data*n)
  55     __rmul__ = __mul__
  56
  57     # the following methods are defined in alphabetical order:
  58     def capitalize(self): return self.__class__(self.data.capitalize())
  59     def center(self, width): return self.__class__(self.data.center(width))
  60     def count(self, sub, start=0, end=sys.maxint):
  61         return self.data.count(sub, start, end)
  62     def encode(self, encoding=None, errors=None): # XXX improve this?
  63         if encoding:
  64             if errors:
  65                 return self.__class__(self.data.encode(encoding, errors))
  66             else:
  67                 return self.__class__(self.data.encode(encoding))
  68         else:
  69             return self.__class__(self.data.encode())
  70     def endswith(self, suffix, start=0, end=sys.maxint):
  71         return self.data.endswith(suffix, start, end)
  72     def expandtabs(self, tabsize=8):
  73         return self.__class__(self.data.expandtabs(tabsize))
  74     def find(self, sub, start=0, end=sys.maxint):
  75         return self.data.find(sub, start, end)
  76     def index(self, sub, start=0, end=sys.maxint):
  77         return self.data.index(sub, start, end)
  78     def isdecimal(self): return self.data.isdecimal()
  79     def isdigit(self): return self.data.isdigit()
  80     def islower(self): return self.data.islower()
  81     def isnumeric(self): return self.data.isnumeric()
  82     def isspace(self): return self.data.isspace()
  83     def istitle(self): return self.data.istitle()
  84     def isupper(self): return self.data.isupper()
  85     def join(self, seq): return self.data.join(seq)
  86     def ljust(self, width): return self.__class__(self.data.ljust(width))
  87     def lower(self): return self.__class__(self.data.lower())
  88     def lstrip(self): return self.__class__(self.data.lstrip())
  89     def replace(self, old, new, maxsplit=-1):
  90         return self.__class__(self.data.replace(old, new, maxsplit))
  91     def rfind(self, sub, start=0, end=sys.maxint):
  92         return self.data.rfind(sub, start, end)
  93     def rindex(self, sub, start=0, end=sys.maxint):
  94         return self.data.rindex(sub, start, end)
  95     def rjust(self, width): return self.__class__(self.data.rjust(width))
  96     def rstrip(self): return self.__class__(self.data.rstrip())
  97     def split(self, sep=None, maxsplit=-1):
  98         return self.data.split(sep, maxsplit)
  99     def splitlines(self, keepends=0): return self.data.splitlines(keepends)
 100     def startswith(self, prefix, start=0, end=sys.maxint):
 101         return self.data.startswith(prefix, start, end)
 102     def strip(self): return self.__class__(self.data.strip())
 103     def swapcase(self): return self.__class__(self.data.swapcase())
 104     def title(self): return self.__class__(self.data.title())
 105     def translate(self, table, deletechars=""):
 106         return self.__class__(self.data.translate(table, deletechars))
 107     def upper(self): return self.__class__(self.data.upper())
 108
 109 class MutableString(UserString):
 110     """mutable string objects
 111
 112     Python strings are immutable objects.  This has the advantage, that
 113     strings may be used as dictionary keys.  If this property isn't needed
 114     and you insist on changing string values in place instead, you may cheat
 115     and use MutableString.
 116
 117     But the purpose of this class is an educational one: to prevent
 118     people from inventing their own mutable string class derived
 119     from UserString and than forget thereby to remove (override) the
 120     __hash__ method inherited from ^UserString.  This would lead to
 121     errors that would be very hard to track down.
 122
 123     A faster and better solution is to rewrite your program using lists."""
 124     def __init__(self, string=""):
 125         self.data = string
 126     def __hash__(self):
 127         raise TypeError, "unhashable type (it is mutable)"
 128     def __setitem__(self, index, sub):
 129         if index < 0 or index >= len(self.data): raise IndexError
 130         self.data = self.data[:index] + sub + self.data[index+1:]
 131     def __delitem__(self, index):
 132         if index < 0 or index >= len(self.data): raise IndexError
 133         self.data = self.data[:index] + self.data[index+1:]
 134     def __setslice__(self, start, end, sub):
 135         start = max(start, 0); end = max(end, 0)
 136         if isinstance(sub, UserString):
 137             self.data = self.data[:start]+sub.data+self.data[end:]
 138         elif isinstance(sub, StringType) or isinstance(sub, UnicodeType):
 139             self.data = self.data[:start]+sub+self.data[end:]
 140         else:
 141             self.data =  self.data[:start]+str(sub)+self.data[end:]
 142     def __delslice__(self, start, end):
 143         start = max(start, 0); end = max(end, 0)
 144         self.data = self.data[:start] + self.data[end:]
 145     def immutable(self):
 146         return UserString(self.data)
 147
 148 if __name__ == "__main__":
 149     # execute the regression test to stdout, if called as a script:
 150     import os
 151     called_in_dir, called_as = os.path.split(sys.argv[0])
 152     called_in_dir = os.path.abspath(called_in_dir)
 153     called_as, py = os.path.splitext(called_as)
 154     sys.path.append(os.path.join(called_in_dir, 'test'))
 155     if '-q' in sys.argv:
 156         import test_support
 157         test_support.verbose = 0
 158     __import__('test_' + called_as.lower())