'Str' object does not support element assignment in Python

Question

I would like to read some characters from a string and put it on another string (as in C).

So my code looks below

import string import re str = "Hello World" j = 0 srr = "" for i in str: srr[j] = i #'str' object does not support item assignment j = j + 1 print (srr) 

In C, the code could be

 i = j = 0; while(str[i] != '\0') { srr[j++] = str [i++]; } 

How can I implement the same in Python?

Answer 1

In Python, strings are immutable, so you cannot change their characters in place.

You can, however, do the following:

 for i in str: srr += i 

Reasons for this: this is a shortcut to:

 for i in str: srr = srr + i 

The above procedure creates a new line with each iteration and stores the link to this new line in srr .

Answer 2

The other answers are correct, but you can of course do something like:

 >>> str1 = "mystring" >>> list1 = list(str1) >>> list1[5] = 'u' >>> str1 = ''.join(list1) >>> print(str1) mystrung >>> type(str1) <type 'str'> 

if you really want it.

Answer 3

Python strings are immutable, so what you're trying to do in C will just be impossible in python. You will need to create a new line.

I would like to read some characters from a string and put it on another string.

Then use the string fragment:

 >>> s1 = 'Hello world!!' >>> s2 = s1[6:12] >>> print s2 world! 

Answer 4

As mentioned above, strings in Python are immutable (you cannot change them in place).

What you are trying to do can be done in many ways:

 # Copy the string foo = 'Hello' bar = foo # Create a new string by joining all characters of the old string new_string = ''.join(c for c in oldstring) # Slice and copy new_string = oldstring[:] 

Answer 5

How about this solution:

str = "Hello World" (as stated in the task) srr = str + ""

Answer 6

Hi, you should try the line splitting method:

 i = "Hello world" output = i.split() j = 'is not enough' print 'The', output[1], j