1#!/usr/bin/env python 2## vim:ts=4:et:nowrap 3"""A user-defined wrapper around string objects 4 5Note: string objects have grown methods in Python 1.6 6This module requires Python 1.6 or later. 7""" 8import sys 9import collections 10 11__all__ = ["UserString","MutableString"] 12 13class UserString(collections.Sequence): 14 def __init__(self, seq): 15 if isinstance(seq, basestring): 16 self.data = seq 17 elif isinstance(seq, UserString): 18 self.data = seq.data[:] 19 else: 20 self.data = str(seq) 21 def __str__(self): return str(self.data) 22 def __repr__(self): return repr(self.data) 23 def __int__(self): return int(self.data) 24 def __long__(self): return long(self.data) 25 def __float__(self): return float(self.data) 26 def __complex__(self): return complex(self.data) 27 def __hash__(self): return hash(self.data) 28 29 def __cmp__(self, string): 30 if isinstance(string, UserString): 31 return cmp(self.data, string.data) 32 else: 33 return cmp(self.data, string) 34 def __contains__(self, char): 35 return char in self.data 36 37 def __len__(self): return len(self.data) 38 def __getitem__(self, index): return self.__class__(self.data[index]) 39 def __getslice__(self, start, end): 40 start = max(start, 0); end = max(end, 0) 41 return self.__class__(self.data[start:end]) 42 43 def __add__(self, other): 44 if isinstance(other, UserString): 45 return self.__class__(self.data + other.data) 46 elif isinstance(other, basestring): 47 return self.__class__(self.data + other) 48 else: 49 return self.__class__(self.data + str(other)) 50 def __radd__(self, other): 51 if isinstance(other, basestring): 52 return self.__class__(other + self.data) 53 else: 54 return self.__class__(str(other) + self.data) 55 def __mul__(self, n): 56 return self.__class__(self.data*n) 57 __rmul__ = __mul__ 58 def __mod__(self, args): 59 return self.__class__(self.data % args) 60 61 # the following methods are defined in alphabetical order: 62 def capitalize(self): return self.__class__(self.data.capitalize()) 63 def center(self, width, *args): 64 return self.__class__(self.data.center(width, *args)) 65 def count(self, sub, start=0, end=sys.maxint): 66 return self.data.count(sub, start, end) 67 def decode(self, encoding=None, errors=None): # XXX improve this? 68 if encoding: 69 if errors: 70 return self.__class__(self.data.decode(encoding, errors)) 71 else: 72 return self.__class__(self.data.decode(encoding)) 73 else: 74 return self.__class__(self.data.decode()) 75 def encode(self, encoding=None, errors=None): # XXX improve this? 76 if encoding: 77 if errors: 78 return self.__class__(self.data.encode(encoding, errors)) 79 else: 80 return self.__class__(self.data.encode(encoding)) 81 else: 82 return self.__class__(self.data.encode()) 83 def endswith(self, suffix, start=0, end=sys.maxint): 84 return self.data.endswith(suffix, start, end) 85 def expandtabs(self, tabsize=8): 86 return self.__class__(self.data.expandtabs(tabsize)) 87 def find(self, sub, start=0, end=sys.maxint): 88 return self.data.find(sub, start, end) 89 def index(self, sub, start=0, end=sys.maxint): 90 return self.data.index(sub, start, end) 91 def isalpha(self): return self.data.isalpha() 92 def isalnum(self): return self.data.isalnum() 93 def isdecimal(self): return self.data.isdecimal() 94 def isdigit(self): return self.data.isdigit() 95 def islower(self): return self.data.islower() 96 def isnumeric(self): return self.data.isnumeric() 97 def isspace(self): return self.data.isspace() 98 def istitle(self): return self.data.istitle() 99 def isupper(self): return self.data.isupper() 100 def join(self, seq): return self.data.join(seq) 101 def ljust(self, width, *args): 102 return self.__class__(self.data.ljust(width, *args)) 103 def lower(self): return self.__class__(self.data.lower()) 104 def lstrip(self, chars=None): return self.__class__(self.data.lstrip(chars)) 105 def partition(self, sep): 106 return self.data.partition(sep) 107 def replace(self, old, new, maxsplit=-1): 108 return self.__class__(self.data.replace(old, new, maxsplit)) 109 def rfind(self, sub, start=0, end=sys.maxint): 110 return self.data.rfind(sub, start, end) 111 def rindex(self, sub, start=0, end=sys.maxint): 112 return self.data.rindex(sub, start, end) 113 def rjust(self, width, *args): 114 return self.__class__(self.data.rjust(width, *args)) 115 def rpartition(self, sep): 116 return self.data.rpartition(sep) 117 def rstrip(self, chars=None): return self.__class__(self.data.rstrip(chars)) 118 def split(self, sep=None, maxsplit=-1): 119 return self.data.split(sep, maxsplit) 120 def rsplit(self, sep=None, maxsplit=-1): 121 return self.data.rsplit(sep, maxsplit) 122 def splitlines(self, keepends=0): return self.data.splitlines(keepends) 123 def startswith(self, prefix, start=0, end=sys.maxint): 124 return self.data.startswith(prefix, start, end) 125 def strip(self, chars=None): return self.__class__(self.data.strip(chars)) 126 def swapcase(self): return self.__class__(self.data.swapcase()) 127 def title(self): return self.__class__(self.data.title()) 128 def translate(self, *args): 129 return self.__class__(self.data.translate(*args)) 130 def upper(self): return self.__class__(self.data.upper()) 131 def zfill(self, width): return self.__class__(self.data.zfill(width)) 132 133class MutableString(UserString, collections.MutableSequence): 134 """mutable string objects 135 136 Python strings are immutable objects. This has the advantage, that 137 strings may be used as dictionary keys. If this property isn't needed 138 and you insist on changing string values in place instead, you may cheat 139 and use MutableString. 140 141 But the purpose of this class is an educational one: to prevent 142 people from inventing their own mutable string class derived 143 from UserString and than forget thereby to remove (override) the 144 __hash__ method inherited from UserString. This would lead to 145 errors that would be very hard to track down. 146 147 A faster and better solution is to rewrite your program using lists.""" 148 def __init__(self, string=""): 149 from warnings import warnpy3k 150 warnpy3k('the class UserString.MutableString has been removed in ' 151 'Python 3.0', stacklevel=2) 152 self.data = string 153 154 # We inherit object.__hash__, so we must deny this explicitly 155 __hash__ = None 156 157 def __setitem__(self, index, sub): 158 if isinstance(index, slice): 159 if isinstance(sub, UserString): 160 sub = sub.data 161 elif not isinstance(sub, basestring): 162 sub = str(sub) 163 start, stop, step = index.indices(len(self.data)) 164 if step == -1: 165 start, stop = stop+1, start+1 166 sub = sub[::-1] 167 elif step != 1: 168 # XXX(twouters): I guess we should be reimplementing 169 # the extended slice assignment/deletion algorithm here... 170 raise TypeError, "invalid step in slicing assignment" 171 start = min(start, stop) 172 self.data = self.data[:start] + sub + self.data[stop:] 173 else: 174 if index < 0: 175 index += len(self.data) 176 if index < 0 or index >= len(self.data): raise IndexError 177 self.data = self.data[:index] + sub + self.data[index+1:] 178 def __delitem__(self, index): 179 if isinstance(index, slice): 180 start, stop, step = index.indices(len(self.data)) 181 if step == -1: 182 start, stop = stop+1, start+1 183 elif step != 1: 184 # XXX(twouters): see same block in __setitem__ 185 raise TypeError, "invalid step in slicing deletion" 186 start = min(start, stop) 187 self.data = self.data[:start] + self.data[stop:] 188 else: 189 if index < 0: 190 index += len(self.data) 191 if index < 0 or index >= len(self.data): raise IndexError 192 self.data = self.data[:index] + self.data[index+1:] 193 def __setslice__(self, start, end, sub): 194 start = max(start, 0); end = max(end, 0) 195 if isinstance(sub, UserString): 196 self.data = self.data[:start]+sub.data+self.data[end:] 197 elif isinstance(sub, basestring): 198 self.data = self.data[:start]+sub+self.data[end:] 199 else: 200 self.data = self.data[:start]+str(sub)+self.data[end:] 201 def __delslice__(self, start, end): 202 start = max(start, 0); end = max(end, 0) 203 self.data = self.data[:start] + self.data[end:] 204 def immutable(self): 205 return UserString(self.data) 206 def __iadd__(self, other): 207 if isinstance(other, UserString): 208 self.data += other.data 209 elif isinstance(other, basestring): 210 self.data += other 211 else: 212 self.data += str(other) 213 return self 214 def __imul__(self, n): 215 self.data *= n 216 return self 217 def insert(self, index, value): 218 self[index:index] = value 219 220if __name__ == "__main__": 221 # execute the regression test to stdout, if called as a script: 222 import os 223 called_in_dir, called_as = os.path.split(sys.argv[0]) 224 called_as, py = os.path.splitext(called_as) 225 if '-q' in sys.argv: 226 from test import test_support 227 test_support.verbose = 0 228 __import__('test.test_' + called_as.lower()) 229