How to convert comma-delimited string to list in Python?
Asked Answered
S

7

269

Given a string that is a sequence of several values separated by a commma:

mStr = 'A,B,C,D,E' 

How do I convert the string to a list?

mList = ['A', 'B', 'C', 'D', 'E']
Smallman answered 21/10, 2011 at 1:33 Comment(1)
Related Convert string representation of list to list in PythonSporophore
O
436

You can use the str.split method.

>>> my_string = 'A,B,C,D,E'
>>> my_list = my_string.split(",")
>>> print my_list
['A', 'B', 'C', 'D', 'E']

If you want to convert it to a tuple, just

>>> print tuple(my_list)
('A', 'B', 'C', 'D', 'E')

If you are looking to append to a list, try this:

>>> my_list.append('F')
>>> print my_list
['A', 'B', 'C', 'D', 'E', 'F']
Oilcan answered 21/10, 2011 at 1:35 Comment(1)
Careful though, splitting an empty string does not return what one might have expected: "".split(",") returns [""] (a list with one element, which is empty string).Patriciapatrician
Y
23

In the case of integers that are included at the string, if you want to avoid casting them to int individually you can do:

mList = [int(e) if e.isdigit() else e for e in mStr.split(',')]

It is called list comprehension, and it is based on set builder notation.

ex:

>>> mStr = "1,A,B,3,4"
>>> mList = [int(e) if e.isdigit() else e for e in mStr.split(',')]
>>> mList
>>> [1,'A','B',3,4]
Yearround answered 30/6, 2015 at 6:54 Comment(0)
B
7

Consider the following in order to handle the case of an empty string:

>>> my_string = 'A,B,C,D,E'
>>> my_string.split(",") if my_string else []
['A', 'B', 'C', 'D', 'E']
>>> my_string = ""
>>> my_string.split(",") if my_string else []
[]
Bookbinding answered 13/4, 2020 at 12:51 Comment(0)
E
5
>>> some_string='A,B,C,D,E'
>>> new_tuple= tuple(some_string.split(','))
>>> new_tuple
('A', 'B', 'C', 'D', 'E')
Eliason answered 21/10, 2011 at 1:39 Comment(0)
O
5

You can split that string on , and directly get a list:

mStr = 'A,B,C,D,E'
list1 = mStr.split(',')
print(list1)

Output:

['A', 'B', 'C', 'D', 'E']

You can also convert it to an n-tuple:

print(tuple(list1))

Output:

('A', 'B', 'C', 'D', 'E')

Ohara answered 18/5, 2020 at 12:38 Comment(2)
Hope It will solve issue but please add explanation of your code with it so user will get perfect understanding which he/she really wants.Ortrude
Looks like a duplicate of the already accepted answer (9 years ago).Hambletonian
C
1

You can use this function to convert comma-delimited single character strings to list-

def stringtolist(x):
    mylist=[]
    for i in range(0,len(x),2):
        mylist.append(x[i])
    return mylist
Certificate answered 30/1, 2019 at 1:55 Comment(0)
E
0
#splits string according to delimeters 
'''
Let's make a function that can split a string
into list according the given delimeters. 
example data: cat;dog:greff,snake/
example delimeters: ,;- /|:
'''
def string_to_splitted_array(data,delimeters):
    #result list
    res = []
    # we will add chars into sub_str until
    # reach a delimeter
    sub_str = ''
    for c in data: #iterate over data char by char
        # if we reached a delimeter, we store the result 
        if c in delimeters: 
            # avoid empty strings
            if len(sub_str)>0:
                # looks like a valid string.
                res.append(sub_str)
                # reset sub_str to start over
                sub_str = ''
        else:
            # c is not a deilmeter. then it is 
            # part of the string.
            sub_str += c
    # there may not be delimeter at end of data. 
    # if sub_str is not empty, we should att it to list. 
    if len(sub_str)>0:
        res.append(sub_str)
    # result is in res 
    return res

# test the function. 
delimeters = ',;- /|:'
# read the csv data from console. 
csv_string = input('csv string:')
#lets check if working. 
splitted_array = string_to_splitted_array(csv_string,delimeters)
print(splitted_array)
Elnaelnar answered 12/10, 2019 at 19:26 Comment(0)

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