# module 'string' -- A collection of string operations
# Warning: most of the code you see here isn't normally used nowadays. With
# Python 1.6, many of these functions are implemented as methods on the
# standard string object. They used to be implemented by a built-in module
# called strop, but strop is now obsolete itself.
"""Common string manipulations.
whitespace -- a string containing all characters considered whitespace
lowercase -- a string containing all characters considered lowercase letters
uppercase -- a string containing all characters considered uppercase letters
letters -- a string containing all characters considered letters
digits -- a string containing all characters considered decimal digits
hexdigits -- a string containing all characters considered hexadecimal digits
octdigits -- a string containing all characters considered octal digits
from warnings import warnpy3k
warnpy3k("the stringold module has been removed in Python 3.0", stacklevel=2)
# Some strings for ctype-style character classification
whitespace = ' \t\n\r\v\f'
lowercase = 'abcdefghijklmnopqrstuvwxyz'
uppercase = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
letters = lowercase + uppercase
hexdigits = digits + 'abcdef' + 'ABCDEF'
# Case conversion helpers
for i in range(256): _idmap = _idmap + chr(i)
# Backward compatible names for exceptions
# convert UPPER CASE letters to lower case
Return a copy of the string s converted to lowercase.
# Convert lower case letters to UPPER CASE
Return a copy of the string s converted to uppercase.
# Swap lower case letters and UPPER CASE
Return a copy of the string s with upper case characters
converted to lowercase and vice versa.
# Strip leading and trailing tabs and spaces
Return a copy of the string s with leading and trailing
# Strip leading tabs and spaces
Return a copy of the string s with leading whitespace removed.
# Strip trailing tabs and spaces
Return a copy of the string s with trailing whitespace
# Split a string into a list of space/tab-separated words
def split(s, sep=None, maxsplit=0):
"""split(str [,sep [,maxsplit]]) -> list of strings
Return a list of the words in the string s, using sep as the
delimiter string. If maxsplit is nonzero, splits into at most
maxsplit words If sep is not specified, any whitespace string
is a separator. Maxsplit defaults to 0.
(split and splitfields are synonymous)
return s.split(sep, maxsplit)
# Join fields with optional separator
def join(words, sep = ' '):
"""join(list [,sep]) -> string
Return a string composed of the words in list, with
intervening occurrences of sep. The default separator is a
(joinfields and join are synonymous)
# for a little bit of speed
# Find substring, raise exception if not found
"""index(s, sub [,start [,end]]) -> int
Like find but raises ValueError when the substring is not found.
return _apply(s.index, args)
# Find last substring, raise exception if not found
"""rindex(s, sub [,start [,end]]) -> int
Like rfind but raises ValueError when the substring is not found.
return _apply(s.rindex, args)
# Count non-overlapping occurrences of substring
"""count(s, sub[, start[,end]]) -> int
Return the number of occurrences of substring sub in string
s[start:end]. Optional arguments start and end are
interpreted as in slice notation.
return _apply(s.count, args)
# Find substring, return -1 if not found
"""find(s, sub [,start [,end]]) -> in
Return the lowest index in s where substring sub is found,
such that sub is contained within s[start,end]. Optional
arguments start and end are interpreted as in slice notation.
return _apply(s.find, args)
# Find last substring, return -1 if not found
"""rfind(s, sub [,start [,end]]) -> int
Return the highest index in s where substring sub is found,
such that sub is contained within s[start,end]. Optional
arguments start and end are interpreted as in slice notation.
return _apply(s.rfind, args)
# Convert string to float
Return the floating point number represented by the string s.
if type(s) == _StringType:
raise TypeError('argument 1: expected string, %s found' %
# Convert string to integer
"""atoi(s [,base]) -> int
Return the integer represented by the string s in the given
base, which defaults to 10. The string s must consist of one
or more digits, possibly preceded by a sign. If base is 0, it
is chosen from the leading characters of s, 0 for octal, 0x or
0X for hexadecimal. If base is 16, a preceding 0x or 0X is
raise TypeError('function requires at least 1 argument: %d given' %
# Don't catch type error resulting from too many arguments to int(). The
# error message isn't compatible but the error type is, and this function
# is complicated enough already.
if type(s) == _StringType:
return _apply(_int, args)
raise TypeError('argument 1: expected string, %s found' %
# Convert string to long integer
"""atol(s [,base]) -> long
Return the long integer represented by the string s in the
given base, which defaults to 10. The string s must consist
of one or more digits, possibly preceded by a sign. If base
is 0, it is chosen from the leading characters of s, 0 for
octal, 0x or 0X for hexadecimal. If base is 16, a preceding
0x or 0X is accepted. A trailing L or l is not accepted,
raise TypeError('function requires at least 1 argument: %d given' %
# Don't catch type error resulting from too many arguments to long(). The
# error message isn't compatible but the error type is, and this function
# is complicated enough already.
if type(s) == _StringType:
return _apply(_long, args)
raise TypeError('argument 1: expected string, %s found' %
"""ljust(s, width) -> string
Return a left-justified version of s, in a field of the
specified width, padded with spaces as needed. The string is
"""rjust(s, width) -> string
Return a right-justified version of s, in a field of the
specified width, padded with spaces as needed. The string is
"""center(s, width) -> string
Return a center version of s, in a field of the specified
width. padded with spaces as needed. The string is never
# This ensures that center(center(s, i), j) = center(s, j)
return ' '*half + s + ' '*(n-half)
# Zero-fill a number, e.g., (12, 3) --> '012' and (-3, 3) --> '-03'
# Decadent feature: the argument may be a string or a number
# (Use of this is deprecated; it should be a string as with ljust c.s.)
"""zfill(x, width) -> string
Pad a numeric string x with zeros on the left, to fill a field
of the specified width. The string x is never truncated.
if type(x) == type(''): s = x
return sign + '0'*(width-n) + s
# Expand tabs in a string.
# Doesn't take non-printing chars into account, but does understand \n.
def expandtabs(s, tabsize=8):
"""expandtabs(s [,tabsize]) -> string
Return a copy of the string s with all tab characters replaced
by the appropriate number of spaces, depending on the current
column, and the tabsize (default 8).
c = ' '*(tabsize - len(line) % tabsize)
# Character translation through look-up table.
def translate(s, table, deletions=""):
"""translate(s,table [,deletechars]) -> string
Return a copy of the string s, where all characters occurring
in the optional argument deletechars are removed, and the
remaining characters have been mapped through the given
translation table, which must be a string of length 256.
return s.translate(table, deletions)
# Capitalize a string, e.g. "aBc dEf" -> "Abc def".
"""capitalize(s) -> string
Return a copy of the string s with only its first character
# Capitalize the words in a string, e.g. " aBc dEf " -> "Abc Def".
def capwords(s, sep=None):
"""capwords(s, [sep]) -> string
Split the argument into words using split, capitalize each
word using capitalize, and join the capitalized words using
join. Note that this replaces runs of whitespace characters by
return join(map(capitalize, s.split(sep)), sep or ' ')
# Construct a translation string
def maketrans(fromstr, tostr):
"""maketrans(frm, to) -> string
Return a translation table (a string of 256 bytes long)
suitable for use in string.translate. The strings frm and to
must be of the same length.
if len(fromstr) != len(tostr):
raise ValueError, "maketrans arguments must have same length"
fromstr = map(ord, fromstr)
for i in range(len(fromstr)):
# Substring replacement (global)
def replace(s, old, new, maxsplit=0):
"""replace (str, old, new[, maxsplit]) -> string
Return a copy of string str with all occurrences of substring
old replaced by new. If the optional argument maxsplit is
given, only the first maxsplit occurrences are replaced.
return s.replace(old, new, maxsplit)
# If string objects do not have methods, then we need to use the old string.py
# library, which uses strop for many more things than just the few outlined
# Try importing optional built-in module "strop" -- if it exists,
# it redefines some string operations that are 100-1000 times faster.
# It also defines values for whitespace, lowercase and uppercase
# that match <ctype.h>'s definitions.
from strop import maketrans, lowercase, uppercase, whitespace
letters = lowercase + uppercase
pass # Use the original versions