How do I modify a single character in a string, in Python? Something like:
a = "hello"
a[2] = "m"
'str' object does not support item assignment.
views:
153answers:
5
+6
A:
Strings are immutable in Python. You can use a list of characters instead:
a = list("hello")
When you want to display the result use ''.join(a):
a[2] = 'm'
print ''.join(a)
Mark Byers
2010-10-05 05:24:36
+5
A:
Try constructing a list from it. When you pass an iterable into a list constructor, it will turn it into a list (this is a bit of an oversimplification, but usually works).
a = list("hello")
a[2] = m
You can then join it back up with ''.join(a).
detly
2010-10-05 05:24:43
Excellent answer.
JoshD
2010-10-05 05:36:42
+6
A:
In python, string are immutable. If you want to change a single character, you'll have to use slicing:
a = "hello"
a = a[:2] + "m" + a[3:]
JoshD
2010-10-05 05:25:01
I suppose this would cost more memory if it's a really big string since you have to join three other strings together to form a new string, right?
Shane
2010-10-05 05:27:47
Oh, yeah! If you need to do a whole bunch of these type of manipulations, it's best to use a list of characters. Unless you happen to already have a string and just happen to want to change one character. Even then, it's probably faster to create and modify a list.
JoshD
2010-10-05 05:29:14
A:
To replace all occurrences of a single character (eg. 'l'), the following would also work:
>>>
>>> a = "hello"
>>> a.replace(a[2],"X")
'heXXo'
>>>
Babil
2010-10-05 06:19:01