CODEWITHSUNDEEP
python
user2547541
user2547541

Reputation:

How to modify a part of string in python

When I execute the following code :

file1 = open("sources.conf", "r");
datalist = list(file1.readlines());
datalist[3][32]= "11";

I get this error: 'str' object does not support item assignment. After reading a bit, I discovered that it is not possible to change the string in python. Is there any other work around for this?

Upvotes: 1

Views: 163

Answers (3)

jh314
jh314

Reputation: 27812

How about this (using slices):

datalist[3] = datalist[3][:31] + "11" + datalist[3][33:]

Also, Python doesn't use ; after each statement.

You can also change your string to a list, and back again:

temp = list(datalist[3])
temp[32:34] = "11"
datalist[3] = "".join(temp)

Upvotes: 0

oleg
oleg

Reputation: 4182

I would advise You to read line by line and modify string If needed (I am not sure that readlines() is the best solution (as It reads whole file into memory)

with open("sources.conf", "r") as file1
    datalist = []
    for i, line in  enumerate(file1):
        if i == 3:
            datalist[i] = line[:32] + "11" + line[33:]
        else:
            datalist[i] = line

or use join methods

datalist[i] = ''.join([line[:32], "11", line[33:]])

Upvotes: 0

Martijn Pieters
Martijn Pieters

Reputation: 1125018

Slice the string and reassign it to the same position in your list:

datalist[3] = datalist[3][:31] + '11' + datalist[3][33:]

Upvotes: 2

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