How would you make a comma-separated string from a list of strings?

my_list = ['a', 'b', 'c', 'd']
my_string = ','.join(my_list)
'a,b,c,d'

This won't work if the list contains integers


And if the list contains non-string types (such as integers, floats, bools, None) then do:

my_string = ','.join(map(str, my_list)) 

Why the map/lambda magic? Doesn't this work?

>>> foo = ['a', 'b', 'c']
>>> print(','.join(foo))
a,b,c
>>> print(','.join([]))

>>> print(','.join(['a']))
a

In case if there are numbers in the list, you could use list comprehension:

>>> ','.join([str(x) for x in foo])

or a generator expression:

>>> ','.join(str(x) for x in foo)

",".join(l) will not work for all cases. I'd suggest using the csv module with StringIO

import StringIO
import csv

l = ['list','of','["""crazy"quotes"and\'',123,'other things']

line = StringIO.StringIO()
writer = csv.writer(line)
writer.writerow(l)
csvcontent = line.getvalue()
# 'list,of,"[""""""crazy""quotes""and\'",123,other things\r\n'