text = 'yeah, but no, but yeah, but no, but yeah'
text.replace('yeah', 'yep')
'yep, but no, but yep, but no, but yep'
text = 'Today is 11/27/2012. PyCon starts 3/13/2013.'
import re
re.sub(r'(\d+)/(\d+)/(\d+)', r'\3-\1-\2', text)
'Today is 2012-11-27. PyCon starts 2013-3-13.'
rom calendar import month_abbr
def change_date(m):
... mon_name = month_abbr[int(m.group(1))]
... return '{} {} {}'.format(m.group(2), mon_name, m.group(3))
...
datepat.sub(change_date, text)
'Today is 27 Nov 2012. PyCon starts 13 Mar 2013.'f
newtext, n = datepat.subn(r'\3-\1-\2', text)
newtext
'Today is 2012-11-27. PyCon starts 2013-3-13.'
n
2