Python Sum of digits in a string function

Question

My function needs to take in a sentence and return the sum of the numbers inside. Any advice?

def sumOfDigits(sentence):
    sumof=0
    for x in sentence:
        if sentence.isdigit(x)== True:
            sumof+=int(x)
    return sumof

Answer 1

Replace this:

if sentence.isdigit(x)== True:

to:

if x.isdigit():

examples:

 >>> "1".isdigit()
 True
 >>> "a".isdigit()
 False

your code should be like:

def sumOfDigits(sentence):
    sumof=0
    for x in sentence:
        if x.isdigit():
            sumof+=int(x)
    return sumof

Some pythonic ways:

Using List Comprehension:

>>> def sumof(sentence):
...     return sum(int(x) for x in sentence if x.isdigit())
... 
>>> sumof("hello123wor6ld")
12

Using Filter, map:

>>> def sumof(sentence):
...     return sum(map(int, filter(str.isdigit, sentence)))
... 
>>> sumof("hello123wor6ld")
12

Using Regular expression, extraction all digit:

>>> import re
>>> def sumof(sentence):
...     return sum(map(int, re.findall("\d",sentence)))
... 
>>> sumof("hello123wor6ld")
12

Answer 2

You have to ask if x is a digit.

def sumOfDigits(sentence):
    sumof=0
    for x in sentence:
        if x.isdigit()== True:
            sumof+=int(x)
    return sumof