Making a list from list of lists

Question

I have the below list of lists

[['Afghanistan,2.66171813,7.460143566,0.490880072,52.33952713,0.427010864,-0.106340349,0.261178523'], ['Albania,4.639548302,9.373718262,0.637698293,69.05165863,0.74961102,-0.035140377,0.457737535']]

I want to create a new list with only the country names.

So

[Afghanistan, Albania]

Currently using this code.

with open(fileName, "r") as f:
    _= next(f)
    row_lst = f.read().split()
    countryLst = [[i] for i in row_lst]

Possible duplicate of [Extract first item of each sublist](https://stackoverflow.com/questions/25050311/extract-first-item-of-each-sublist) — Chris, Sep 19 '19 at 04:34
The inner lists seem to be made of a single string. Possibly a misplaced quote. — rdas, Sep 19 '19 at 04:35
It reads in as a string per row, how do I make it not do that? — Electric_Sheep01, Sep 19 '19 at 04:37

shaik moeed · Accepted Answer · 2019-09-19T05:01:34.393

1

Try this, using split(',') as your first element in list of list is string separated by comma.

>>> lst = [['Afghanistan,2.66171813,7.460143566,0.490880072,52.33952713,0.427010864,-0.106340349,0.261178523'], ['Albania,4.639548302,9.373718262,0.637698293,69.05165863,0.74961102,-0.035140377,0.457737535']]

Output:

>>> [el[0].split(',')[0] for el in lst]                       
['Afghanistan', 'Albania']

Explanation:

# el[0] gives the first element in you list which a string.
# .split(',') returns a list of elements after spliting by `,`
# [0] finally selecting your first element as required.

Edit-1:

Using regex,

pattern = r'([a-zA-Z]+)'
new_lst = []
for el in lst:
    new_lst+=re.findall(pattern, el[0])

>>> new_lst     # output          
['Afghanistan', 'Albania']

edited Sep 19 '19 at 05:01

answered Sep 19 '19 at 04:35

shaik moeed

5,300
1
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This worked but when putting split(',') first in the row_lst it gives me an error. Putting the code you shared above under countryLst gave me what I want but I don't think its efficient – Electric_Sheep01 Sep 19 '19 at 04:42
@Electric_Sheep01 *but I don't think its efficient* why? You are not doing any extra steps to achieve results. – shaik moeed Sep 19 '19 at 04:46

score 0 · Answer 2 · answered Sep 19 '19 at 04:39

0

Looks like a CSV file. Use the csv module

Ex:

import csv

with open(fileName, "r") as f:
   reader = csv.reader(f)
   next(reader) #Skip header
   country = [row[0] for row in reader]

answered Sep 19 '19 at 04:39

Rakesh

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Making a list from list of lists

2 Answers2