How can I split and parse a string in Python? [duplicate]

Python string parsing walkthrough

Split a string on space, get a list, show its type, print it out:

el@apollo:~/foo$ python >>> mystring = "What does the fox say?" >>> mylist = mystring.split(" ") >>> print type(mylist) <type 'list'> >>> print mylist ['What', 'does', 'the', 'fox', 'say?'] 

If you have two delimiters next to each other, empty string is assumed:

el@apollo:~/foo$ python >>> mystring = "its so fluffy im gonna DIE!!!" >>> print mystring.split(" ") ['its', '', 'so', '', '', 'fluffy', '', '', 'im', 'gonna', '', '', '', 'DIE!!!'] 

Split a string on underscore and grab the 5th item in the list:

el@apollo:~/foo$ python >>> mystring = "Time_to_fire_up_Kowalski's_Nuclear_reactor." >>> mystring.split("_")[4] "Kowalski's" 

Collapse multiple spaces into one

el@apollo:~/foo$ python >>> mystring = 'collapse these spaces' >>> mycollapsedstring = ' '.join(mystring.split()) >>> print mycollapsedstring.split(' ') ['collapse', 'these', 'spaces'] 

When you pass no parameter to Python's split method, the documentation states: "runs of consecutive whitespace are regarded as a single separator, and the result will contain no empty strings at the start or end if the string has leading or trailing whitespace".

Hold onto your hats boys, parse on a regular expression:

el@apollo:~/foo$ python >>> mystring = 'zzzzzzabczzzzzzdefzzzzzzzzzghizzzzzzzzzzzz' >>> import re >>> mylist = re.split("[a-m]+", mystring) >>> print mylist ['zzzzzz', 'zzzzzz', 'zzzzzzzzz', 'zzzzzzzzzzzz'] 

The regular expression "[a-m]+" means the lowercase letters a through m that occur one or more times are matched as a delimiter. re is a library to be imported.

Or if you want to chomp the items one at a time:

el@apollo:~/foo$ python >>> mystring = "theres coffee in that nebula" >>> mytuple = mystring.partition(" ") >>> print type(mytuple) <type 'tuple'> >>> print mytuple ('theres', ' ', 'coffee in that nebula') >>> print mytuple[0] theres >>> print mytuple[2] coffee in that nebula 

If it's always going to be an even LHS/RHS split, you can also use the partition method that's built into strings. It returns a 3-tuple as (LHS, separator, RHS) if the separator is found, and (original_string, '', '') if the separator wasn't present:

>>> "2.7.0_bf4fda703454".partition('_') ('2.7.0', '_', 'bf4fda703454') >>> "shazam".partition("_") ('shazam', '', '')