Change language

# Python — Get the sum of numbers in a list of strings

|

Method # 1: Using loop + `int()`
This is a brute force method to accomplish this task. In this, we start a loop for the entire list, convert each line to an integer, and do the summation over the list and store in a separate list.

` `

` # Python3 code to demonstrate how it works # Summing lists of string integers # using loop + int ()   # initialize the list test_list = [[[ ’ 1’ , ’4’ ], [ ’5’ , ’ 6’ ], [ ’7’ , ’10’ ]]    # print original list print ( " The original list: " + str (test_list) )   # Summing lists of string integers # using loop + int () res = [] for sub in test_list: par_sum = 0   for ele in sub: par_sum = par_sum + int (ele) res.append (par_sum)   # print result print ( "List after summation of nested string lists:" + str (res)) `

` ` Output:

` The original list: [[’1’,’ 4’], [’5’,’ 6’], [’7’,’ 10 ’]] List after summation of nested string lists: [5, 11, 17] `

Method # 2: Using ` sum () + int () ` + comprehension list
This is shorthand to accomplish this task. In this we loop through the lists using comprehension and extract the sum using sum ().

 ` # Python3 code to demonstrate how it works ` ` # Summing lists of string integers ` ` # using sum () + int () + list comprehension `   ` # initialize the list ` ` test_list ` ` = ` ` [[[` `’ 1’ ` `, ` ` ’4’ ` `], [` ` ’5’ ` `, ` `’ 6’ ` `], [` ` ’7’ ` `, ` `’ 10’ ` `]] ` ` `  ` # print original list ` ` print ` ` (` ` "The original list:" ` ` + ` ` str ` ` (test_list)) `   ` # Summing lists of string integers ` ` # using sum () + int () + list comprehension ` ` res ` ` = ` ` [` ` sum ` ` (` ` int ` ` (ele) ` ` for ` ` ele ` ` in ` ` sub) ` ` for ` ` sub ` ` in ` ` test_list] `   ` # print result ` ` print ` ` (` ` " List after summation of nested string lists: "` ` + ` ` str ` ` (res) ) `

Output:

` The original list: [[’1’,’ 4’], [’5’,’ 6’], [’7’,’ 10’]] List after summation of nested string lists: [5, 11, 17] `

## Shop

Learn programming in R: courses

\$

Best Python online courses for 2022

\$

Best laptop for Fortnite

\$

Best laptop for Excel

\$

Best laptop for Solidworks

\$

Best laptop for Roblox

\$

Best computer for crypto mining

\$

Best laptop for Sims 4

\$

Latest questions

NUMPYNUMPY

Common xlabel/ylabel for matplotlib subplots

NUMPYNUMPY

How to specify multiple return types using type-hints

NUMPYNUMPY

Why do I get "Pickle - EOFError: Ran out of input" reading an empty file?

NUMPYNUMPY

Flake8: Ignore specific warning for entire file

NUMPYNUMPY

glob exclude pattern

NUMPYNUMPY

How to avoid HTTP error 429 (Too Many Requests) python

NUMPYNUMPY

Python CSV error: line contains NULL byte

NUMPYNUMPY

csv.Error: iterator should return strings, not bytes

## Wiki

Python | How to copy data from one Excel sheet to another

Common xlabel/ylabel for matplotlib subplots

Check if one list is a subset of another in Python

How to specify multiple return types using type-hints

Printing words vertically in Python

Python Extract words from a given string

Cyclic redundancy check in Python

Finding mean, median, mode in Python without libraries