A string object has a number of method
functions. These can be grouped arbitrarily into transformations, which
create new strings from old, and information,
which returns a fact about a string. In all of
the following method functions, we'll assume a
string object named
s.
The following string transformation
functions create a new string from an existing
string.
s.capitalize
→ string
Create a copy of the strings with only its first character
capitalized.
s.center(width
) → string
Create a copy of the strings centered in a
string of length
width. Padding is done using spaces.
s.encode(encoding,
[errors]) → string
Return an encoded string version of
s. Default
encoding is the current default
string encoding.
errors may be given to set a different
error handling scheme. Default is 'strict' meaning that encoding
errors raise a ValueError. Other
possible values are 'ignore' and 'replace'.
s.expandtabs
([tabsize] ) →
string
Return a copy of s where all tab
characters are expanded using spaces. If
tabsize is not given, a tab size of 8
characters is assumed.
s.join(sequence
) → string
Return a string which is the
concatenation of the strings in the
sequence. The separator between elements is
s.
s.ljust(width
) → string
Return s left justified in a
string of length
width. Padding is done using spaces.
s.lower
→ string
Return a copy of s converted to
lowercase.
s.lstrip
→ string
Return a copy of s with leading
whitespace removed.
s.replace(old,
new,
[maxsplit]) → string
Return a copy of strings with all occurrences of substring
old replaced by new.
If the optional argument maxsplit is given,
only the first maxsplit occurrences are
replaced.
s.rjust(width
) → string
Return s right justified in a
string of length
width. Padding is done using spaces.
s.rstrip
→ string
Return a copy of s with trailing
whitespace removed.
s.strip →
string
Return a copy of s with leading
and trailing whitespace removed.
s.swapcase
→ string
Return a copy of s with uppercase
characters converted to lowercase and vice versa.
s.title
→ string
Return a titlecased version of s,
i.e. words start with uppercase characters, all remaining cased
characters have lowercase.
s.translate(table,
[deletechars]) → string
Return a copy of the strings, 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. The translation
tables are built using the string.maketrans
function in the string module.
s.upper
→ string
Return a copy of s converted to
uppercase.
The following accessor methods provide information about a
string.
s.count(sub,
[start, ]
[end]) → int
Return the number of occurrences of substring
sub in strings[start:end].
Optional arguments start and
end are interpreted as in slice
notation.
s., (endswithsuffix,
[start, ]
[end]) → boolean
Return True if
s ends with the specified
suffix, otherwise return
False. With optional
start, or end, test
s[start:end].
The suffix can be a single string or a sequence of individual
strings.
s., (findsub,
[start, ]
[end]) → int
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.
s., (indexsub,
[start, ]
[end]) → int
Like s.find
but raise ValueError when the
substring is not found.
s., (isalnum)
→ boolean
Return True if all characters in
s are alphanumeric and there is at
least one character in s,
False otherwise.
s., (isalpha)
→ boolean
Return True if all characters in
s are alphabetic and there is at least
one character in s,
False otherwise.
s., (isdigit)
→ boolean
Return True if all characters in
s are digits and there is at least one
character in s,
False otherwise.
s., (islower)
→ boolean
Return True if all characters in
s are lowercase and there is at least
one cased character in s,
False otherwise.
s., (isspace)
→ boolean
Return True if all characters in
s are whitespace and there is at least
one character in s,
False otherwise.
s., (istitle)
→ boolean
Return True if
s is a titlecased
string, i.e. uppercase characters may only
follow uncased characters and lowercase characters only cased
ones, False otherwise.
s., (isupper)
→ boolean
Return True if all characters in
s are uppercase and there is at least
one cased character in s,
False otherwise.
s., (rfindsub,
[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.
s., (rindexsub,
[start, ]
[end]) → int
Like s.rfind but raise
ValueError when the substring is
not found.
s., (startswithprefix,
[start, ]
[end]) → boolean
Return True if
s starts with the specified
prefix, otherwise return
False. With optional
start, or end, test
s[start:end].
The prefix can be a single string or a sequence of individual
strings.
The following generators create another kind of object, usually a
sequence, from a string.
s.partition(sep)
→ 3-tuple
Return a three-tuple of the text
prior to the first occurance of sep in the
strings, the
sep as the delimiter, and the text after
the first occurance of the separator. If the separator doesn't
occur, all of the input string is in the first element of the
3-tuple; the other two elements are empty strings.
s.split(sep,
[maxsplit]) → sequence
Return a list of the words in the
strings, using
sep as the delimiter
string. If maxsplit
is given, at most maxsplit splits are done.
If sep is not specified, any whitespace
string is a separator.
s.splitlines
([keepends] ) →
sequence
Return a list of the lines in
s, breaking at line boundaries. Line
breaks are not included in the resulting
list unless keepends
is given and true.
Here's another example of using some of the
string methods and slicing operations.
for arg in sys.argv[1:]:
argCap= arg.upper()
if argCap[:2] == "-D":
if argCap[2:] == "MYSQL":
print "MySQL Connection"
elif argCap[2:] == "POSTGRES":
print "Postgres Connection"
elsif argCap[2:] == "SQLITE"
print "SQLite Connection"
else:
print "'%s' is an unknown -D option" % argCap[2:]
else:
parse other option types
We use the upper function to translate
the provided parameter to upper case. This simplifies the comparison
between the parameters. We take slices of each parameter
string to compare the initial portion to see if
it is -D, and we compare the final portion to a
number of literal strings. Additionally, we use
the formatting operation, %, to format an error
report.
Published under the terms of the Open Publication License
