The following list of functions are also defined as methods of string and
Unicode objects; see ``String Methods'' (section
3.6.1) for more information on those. You should consider
these functions as deprecated, although they will not be removed until Python
3.0. The functions defined in this module are:
atof(
s)
Deprecated since release 2.0.
Use the float() built-in function.
Convert a string to a floating point number. The string must have
the standard syntax for a floating point literal in Python,
optionally preceded by a sign ("+" or "-"). Note that
this behaves identical to the built-in function
float() when passed a string.
Note:
When passing in a string, values for NaN
and Infinity may be returned, depending on the
underlying C library. The specific set of strings accepted which
cause these values to be returned depends entirely on the C library
and is known to vary.
atoi(
s[, base])
Deprecated since release 2.0.
Use the int() built-in function.
Convert string s to an integer in the given base. The
string must consist of one or more digits, optionally preceded by a
sign ("+" or "-"). The base defaults to 10. If it
is 0, a default base is chosen depending on the leading characters
of the string (after stripping the sign): "0x" or "0X" means 16, "0" means 8, anything else means 10. If base
is 16, a leading "0x" or "0X" is always accepted, though
not required. This behaves identically to the built-in function
int() when passed a string. (Also note: for a more
flexible interpretation of numeric literals, use the built-in
function eval().)
atol(
s[, base])
Deprecated since release 2.0.
Use the long() built-in function.
Convert string s to a long integer in the given base.
The string must consist of one or more digits, optionally preceded
by a sign ("+" or "-"). The base argument has the
same meaning as for atoi(). A trailing "l" or
"L" is not allowed, except if the base is 0. Note that when
invoked without base or with base set to 10, this
behaves identical to the built-in function
long() when passed a string.
capitalize(
word)
Return a copy of word with only its first character capitalized.
expandtabs(
s[, tabsize])
Expand tabs in a string replacing them by one or more spaces,
depending on the current column and the given tab size. The column
number is reset to zero after each newline occurring in the string.
This doesn't understand other non-printing characters or escape
sequences. The tab size defaults to 8.
find(
s, sub[, start[,end]])
Return the lowest index in s where the substring sub is
found such that sub is wholly contained in
s[start:end]. Return -1 on failure.
Defaults for start and end and interpretation of
negative values is the same as for slices.
rfind(
s, sub[, start[, end]])
Like find() but find the highest index.
index(
s, sub[, start[, end]])
Like find() but raise ValueError when the
substring is not found.
rindex(
s, sub[, start[, end]])
Like rfind() but raise ValueError when the
substring is not found.
count(
s, sub[, start[, end]])
Return the number of (non-overlapping) occurrences of substring
sub in string s[start:end].
Defaults for start and end and interpretation of
negative values are the same as for slices.
lower(
s)
Return a copy of s, but with upper case letters converted to
lower case.
split(
s[, sep[, maxsplit]])
Return a list of the words of the string s. If the optional
second argument sep is absent or None, the words are
separated by arbitrary strings of whitespace characters (space, tab,
newline, return, formfeed). If the second argument sep is
present and not None, it specifies a string to be used as the
word separator. The returned list will then have one more item
than the number of non-overlapping occurrences of the separator in
the string. The optional third argument maxsplit defaults to
0. If it is nonzero, at most maxsplit number of splits occur,
and the remainder of the string is returned as the final element of
the list (thus, the list will have at most maxsplit+1
elements).
The behavior of split on an empty string depends on the value of sep.
If sep is not specified, or specified as None, the result will
be an empty list. If sep is specified as any string, the result will
be a list containing one element which is an empty string.
rsplit(
s[, sep[, maxsplit]])
Return a list of the words of the string s, scanning s
from the end. To all intents and purposes, the resulting list of
words is the same as returned by split(), except when the
optional third argument maxsplit is explicitly specified and
nonzero. When maxsplit is nonzero, at most maxsplit
number of splits - the rightmost ones - occur, and the remainder
of the string is returned as the first element of the list (thus, the
list will have at most maxsplit+1 elements).
New in version 2.4.
splitfields(
s[, sep[, maxsplit]])
This function behaves identically to split(). (In the
past, split() was only used with one argument, while
splitfields() was only used with two arguments.)
join(
words[, sep])
Concatenate a list or tuple of words with intervening occurrences of
sep. The default value for sep is a single space
character. It is always true that
"string.join(string.split(s, sep), sep)" equals s.
joinfields(
words[, sep])
This function behaves identically to join(). (In the past,
join() was only used with one argument, while
joinfields() was only used with two arguments.)
Note that there is no joinfields() method on string
objects; use the join() method instead.
lstrip(
s[, chars])
Return a copy of the string with leading characters removed. If
chars is omitted or None, whitespace characters are
removed. If given and not None, chars must be a string;
the characters in the string will be stripped from the beginning of
the string this method is called on.
Changed in version 2.2.3:
The chars parameter was added. The chars
parameter cannot be passed in earlier 2.2 versions.
rstrip(
s[, chars])
Return a copy of the string with trailing characters removed. If
chars is omitted or None, whitespace characters are
removed. If given and not None, chars must be a string;
the characters in the string will be stripped from the end of the
string this method is called on.
Changed in version 2.2.3:
The chars parameter was added. The chars
parameter cannot be passed in earlier 2.2 versions.
strip(
s[, chars])
Return a copy of the string with leading and trailing characters
removed. If chars is omitted or None, whitespace
characters are removed. If given and not None, chars
must be a string; the characters in the string will be stripped from
the both ends of the string this method is called on.
Changed in version 2.2.3:
The chars parameter was added. The chars
parameter cannot be passed in earlier 2.2 versions.
swapcase(
s)
Return a copy of s, but with lower case letters
converted to upper case and vice versa.
translate(
s, table[, deletechars])
Delete all characters from s that are in deletechars (if
present), and then translate the characters using table, which
must be a 256-character string giving the translation for each
character value, indexed by its ordinal.
upper(
s)
Return a copy of s, but with lower case letters converted to
upper case.
ljust(
s, width)
rjust(
s, width)
center(
s, width)
These functions respectively left-justify, right-justify and center
a string in a field of given width. They return a string that is at
least width characters wide, created by padding the string
s with spaces until the given width on the right, left or both
sides. The string is never truncated.
zfill(
s, width)
Pad a numeric string on the left with zero digits until the given
width is reached. Strings starting with a sign are handled
correctly.
replace(
str, old, new[, maxreplace])
Return a copy of string str with all occurrences of substring
old replaced by new. If the optional argument
maxreplace is given, the first maxreplace occurrences are
replaced.
