substitute a character in string python code example

Example 1: python replace all occurrences in string

>>> 'no one knows how'.replace('no', 'yes')
'yes one kyesws how'

Example 2: replace character in string python

>>> x = 'xpple bxnxnx cherry'
>>> a = x.replace(x,a)  # replaces x with a
'apple banana cherry'

>>> first_a = x.replace(x,a,1)  # only replaces first a
'apple bxnxnx cherry'

Example 3: python change character in string

mytext = 'Hello Zorld'
mytext = mytext.replace('Z', 'W')
print mytext,