replace method for python strings

Question

I have a string S = 'spam'

When I use the method replace as S.replace('pa', 'xx')

S.replace('pa', 'xx')

The output I get is -

Out[1044]: "sxxm's"

Why then are the python strings known to be immutable ?

Who says the string object `S` references itself is altered? You got a *new string* back, which was echoed. — Martijn Pieters, Sep 27 '16 at 12:07
Try `T = S.replace('pa', 'xx')` and you'll see that `S` is unaltered afterwards. [*"Return a copy of the string with all occurrences of substring old replaced by new."*](https://docs.python.org/3/library/stdtypes.html#str.replace) — jonrsharpe, Sep 27 '16 at 12:07

score 1 · Accepted Answer · answered Sep 27 '16 at 12:09

1

S = 'spam'
S.replace('pa', 'xx')
print S

You will get the same string 'spam'

answered Sep 27 '16 at 12:09

FallAndLearn

score -1 · Answer 2 · answered Sep 27 '16 at 12:10

-1

You are not saving the return value.

Snew = S.replace('pa', 'xx')

should work

answered Sep 27 '16 at 12:10

Marshall

2 Answers2