You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
382 lines
11 KiB
382 lines
11 KiB
"""A collection of string operations (most are no longer used in Python 1.6). |
|
|
|
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. |
|
|
|
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 |
|
punctuation -- a string containing all characters considered punctuation |
|
printable -- a string containing all characters considered printable |
|
|
|
""" |
|
|
|
# Some strings for ctype-style character classification |
|
whitespace = ' \t\n\r\v\f' |
|
lowercase = 'abcdefghijklmnopqrstuvwxyz' |
|
uppercase = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' |
|
letters = lowercase + uppercase |
|
ascii_lowercase = lowercase |
|
ascii_uppercase = uppercase |
|
ascii_letters = ascii_lowercase + ascii_uppercase |
|
digits = '0123456789' |
|
hexdigits = digits + 'abcdef' + 'ABCDEF' |
|
octdigits = '01234567' |
|
punctuation = """!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~""" |
|
printable = digits + letters + punctuation + whitespace |
|
|
|
# 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=-1): |
|
"""split(s [,sep [,maxsplit]]) -> list of strings |
|
|
|
Return a list of the words in the string s, using sep as the |
|
delimiter string. If maxsplit is given, splits at no more than |
|
maxsplit places (resulting in at most maxsplit+1 words). If sep |
|
is not specified, any whitespace string is a separator. |
|
|
|
(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 |
|
|
|
# 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 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 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 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 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 s.rfind(*args) |
|
|
|
# for a bit of speed |
|
_float = float |
|
_int = int |
|
_long = long |
|
try: |
|
_StringTypes = (str, unicode) |
|
except NameError: |
|
_StringTypes = (str,) |
|
|
|
# Convert string to float |
|
def atof(s): |
|
"""atof(s) -> float |
|
|
|
Return the floating point number represented by the string s. |
|
|
|
""" |
|
return _float(s) |
|
|
|
|
|
# Convert string to integer |
|
def atoi(s , base=10): |
|
"""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. |
|
|
|
""" |
|
return _int(s, base) |
|
|
|
|
|
# Convert string to long integer |
|
def atol(s, base=10): |
|
"""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. |
|
|
|
""" |
|
return _long(s, base) |
|
|
|
|
|
# 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. |
|
|
|
""" |
|
return s.ljust(width) |
|
|
|
# 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. |
|
|
|
""" |
|
return s.rjust(width) |
|
|
|
# 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. |
|
|
|
""" |
|
return s.center(width) |
|
|
|
# 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 not isinstance(x, _StringTypes): |
|
x = repr(x) |
|
return x.zfill(width) |
|
|
|
# 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). |
|
|
|
""" |
|
return s.expandtabs(tabsize) |
|
|
|
# Character translation through look-up table. |
|
def translate(s, table, deletions=""): |
|
"""translate(s,table [,deletions]) -> string |
|
|
|
Return a copy of the string s, where all characters occurring |
|
in the optional argument deletions are removed, and the |
|
remaining characters have been mapped through the given |
|
translation table, which must be a string of length 256. The |
|
deletions argument is not allowed for Unicode strings. |
|
|
|
""" |
|
if deletions: |
|
return s.translate(table, deletions) |
|
else: |
|
# Add s[:0] so that if s is Unicode and table is an 8-bit string, |
|
# table is converted to Unicode. This means that table *cannot* |
|
# be a dictionary -- for that feature, use u.translate() directly. |
|
return s.translate(table + s[:0]) |
|
|
|
# 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". |
|
# See also regsub.capwords(). |
|
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=-1): |
|
"""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) |
|
|
|
|
|
# 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
|
|
|