How do I read the first line of a string?
PythonStringPython Problem Overview
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'
Python Solutions
Solution 1 - Python
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.
Solution 2 - Python
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
Solution 3 - Python
You can use split():
my_string = """This is my first line,
this is my second line, and...
...this is my fourth line!"""
lines = my_string.split('\n')