ref: 1c4c82277ea368739af6a4666ae530bbcfae71cb
dir: /sys/lib/python/stringold.py/
# 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.
Public module variables:
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
"""
# Some strings for ctype-style character classification
whitespace = ' \t\n\r\v\f'
lowercase = 'abcdefghijklmnopqrstuvwxyz'
uppercase = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
letters = lowercase + uppercase
digits = '0123456789'
hexdigits = digits + 'abcdef' + 'ABCDEF'
octdigits = '01234567'
# Case conversion helpers
_idmap = ''
for i in range(256): _idmap = _idmap + chr(i)
del i
# Backward compatible names for exceptions
index_error = ValueError
atoi_error = ValueError
atof_error = ValueError
atol_error = ValueError
# convert UPPER CASE letters to lower case
def lower(s):
"""lower(s) -> string
Return a copy of the string s converted to lowercase.
"""
return s.lower()
# Convert lower case letters to UPPER CASE
def upper(s):
"""upper(s) -> string
Return a copy of the string s converted to uppercase.
"""
return s.upper()
# Swap lower case letters and UPPER CASE
def swapcase(s):
"""swapcase(s) -> string
Return a copy of the string s with upper case characters
converted to lowercase and vice versa.
"""
return s.swapcase()
# Strip leading and trailing tabs and spaces
def strip(s):
"""strip(s) -> string
Return a copy of the string s with leading and trailing
whitespace removed.
"""
return s.strip()
# Strip leading tabs and spaces
def lstrip(s):
"""lstrip(s) -> string
Return a copy of the string s with leading whitespace removed.
"""
return s.lstrip()
# Strip trailing tabs and spaces
def rstrip(s):
"""rstrip(s) -> string
Return a copy of the string s with trailing whitespace
removed.
"""
return s.rstrip()
# 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)
splitfields = split
# 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
single space.
(joinfields and join are synonymous)
"""
return sep.join(words)
joinfields = join
# for a little bit of speed
_apply = apply
# Find substring, raise exception if not found
def index(s, *args):
"""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
def rindex(s, *args):
"""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
def count(s, *args):
"""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
def find(s, *args):
"""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 -1 on failure.
"""
return _apply(s.find, args)
# Find last substring, return -1 if not found
def rfind(s, *args):
"""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 -1 on failure.
"""
return _apply(s.rfind, args)
# for a bit of speed
_float = float
_int = int
_long = long
_StringType = type('')
# Convert string to float
def atof(s):
"""atof(s) -> float
Return the floating point number represented by the string s.
"""
if type(s) == _StringType:
return _float(s)
else:
raise TypeError('argument 1: expected string, %s found' %
type(s).__name__)
# Convert string to integer
def atoi(*args):
"""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
accepted.
"""
try:
s = args[0]
except IndexError:
raise TypeError('function requires at least 1 argument: %d given' %
len(args))
# 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)
else:
raise TypeError('argument 1: expected string, %s found' %
type(s).__name__)
# Convert string to long integer
def atol(*args):
"""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,
unless base is 0.
"""
try:
s = args[0]
except IndexError:
raise TypeError('function requires at least 1 argument: %d given' %
len(args))
# 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)
else:
raise TypeError('argument 1: expected string, %s found' %
type(s).__name__)
# Left-justify a string
def ljust(s, width):
"""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
never truncated.
"""
n = width - len(s)
if n <= 0: return s
return s + ' '*n
# Right-justify a string
def rjust(s, width):
"""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
never truncated.
"""
n = width - len(s)
if n <= 0: return s
return ' '*n + s
# Center a string
def center(s, width):
"""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
truncated.
"""
n = width - len(s)
if n <= 0: return s
half = n/2
if n%2 and width%2:
# This ensures that center(center(s, i), j) = center(s, j)
half = half+1
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.)
def zfill(x, width):
"""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
else: s = repr(x)
n = len(s)
if n >= width: return s
sign = ''
if s[0] in ('-', '+'):
sign, s = s[0], s[1:]
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).
"""
res = line = ''
for c in s:
if c == '\t':
c = ' '*(tabsize - len(line) % tabsize)
line = line + c
if c == '\n':
res = res + line
line = ''
return res + line
# 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".
def capitalize(s):
"""capitalize(s) -> string
Return a copy of the string s with only its first character
capitalized.
"""
return s.capitalize()
# 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
a single space.
"""
return join(map(capitalize, s.split(sep)), sep or ' ')
# Construct a translation string
_idmapL = None
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"
global _idmapL
if not _idmapL:
_idmapL = map(None, _idmap)
L = _idmapL[:]
fromstr = map(ord, fromstr)
for i in range(len(fromstr)):
L[fromstr[i]] = tostr[i]
return join(L, "")
# 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)
# XXX: transitional
#
# 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
# below.
try:
''.upper
except AttributeError:
from stringold import *
# 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.
try:
from strop import maketrans, lowercase, uppercase, whitespace
letters = lowercase + uppercase
except ImportError:
pass # Use the original versions