we can split a string by a separator. the separator can be one or more characters
just_len = 55
line = 'asdf fjdk; afed, fjek,asdf,foo'
print('string split function'.ljust(just_len),
line.split(','))
but we can NOT split a string by either , or ;
print('string split does not support either concept'.ljust(just_len), line.split(',;'))
but we could use powerful regular expression to split strings the downside is that it's not so obvious, it's always good to add some explanations for regular expression split by either ; or , or space and followed by any number of spaces
import re
print('we can use regular express to support either concept'.ljust(just_len),
re.split(r'[;,\s]\s*', line))
if we remove followed by any number of spaces then string like ', ' we are separated, there is an empty string item created
print('no suffix \s* means every character is a separator'.ljust(just_len), re.split(r'[;,\s]', line))
print('while we could remove it by list comprehension'.ljust(just_len), [s for s in re.split(r'[;,\s]', line) if s])
if using capture group (parentheses added in regular expression) then the separation self also will be included in the result
fields = re.split(r'(;|,|\s)\s*', line)
print('delimiters will be in result if using group'.ljust(just_len), fields)
the value will be item 0,2,4,6... the delimiters will be 1,3,5,7
delimiters = fields[1::2] + ['']
values = fields[::2]
print('start from 1 and every second item are delimiters'.ljust(just_len), delimiters)
print('start from 0 and every second item are values'.ljust(just_len), values)
worth to notice that if there are consequence string with delimiters ';,' then there will be an empty string item in the result
line = 'asdf fjdk;, afed, fjek,asdf,foo'
fields = re.split(r'(?:;|,|\s)\s*', line)
print('between two delimiters will create an item in result'.ljust(just_len), fields)