How do I read the first line of a string? [duplicate]

Question

my_string = """This is my first line, this is my second line, and...  ...this is my fourth line!""" 

How can I store the first line of that (This is my first line,) into a separate string? I attempted to use .readline() from another similar question, however I get this error:

AttributeError: 'str' object has no attribute 'readline'

Answer 1

Use str.partition() to split the string on a newline, and grab the first item from the result:

my_string.partition('\n')[0] 

This is the most efficient method if you only need to split a string in a single location. You could use str.split() too:

my_string.split('\n', 1)[0] 

You do then need to tell the method to only split once, on the first newline, as we discard the rest.

Or you could use the .splitlines() method:

my_string.splitlines()[0] 

but this has to create separate strings for every newline in the input string so is not nearly as efficient.

Answer 2

readline is used i conjuction with a stream. you could use StringIO if you insist on using readline:

from StringIO import StringIO  sio = StringIO(my_string) for sline in sio.readlines():     print sline 

I would do

 for line in my_string.split('\n'):         print line 

or do

import re for line in re.split('\n', my_string):     print line