Question

Prob. 3 Develop a function that meets the requirement in the document string of sumDigits: 1 def sumDigits (s): 'Inputsisastring.The returned value should be the sum of all numerical digits in s In addition if the first non-empty char ofs is a minus sign then the returned value should add a minus sign to the sum E.g., sumDigits("A33S%4C++D ') should return 10, sunn Digits('-+z33S%4-D') 6 and sunn Digits (' -A+3-3-4»D') should both return -10 That is minus sign matters only when it is the first non-empty char You may need to look up s.isdigitO,s.lstrip() from help (str) 10

I will post what I currently have and also the tests for it. Unfortunately it randomly fails some tests so I was wondering if anyone could help.

def sumDigits(s):
'''Input s is a string. The returned value should be the sum of all numerical
digits in s.
In addition, if the first non-empty char of s is a minus sign, then the
returned value should add a minus sign to the sum.
E.g., sumDigits('A33$%4C*+D') should return 10, sumDigits('-+z33$%4-D')
and sumDigits(' -A+3-3-4*D') should both return -10.
That is, minus sign matters only when it is the first non-empty char.
You may need to look up s.isdigit(), s.lstrip(' ') from help(str).  
'''
r = 0
f = 1
flag = 0
  
for i in s:
if i.isdigit():
r = r+ int(i)
if flag == 0:
if i =='-':
f = -1
flag = 1
sumofdigits= f*r
return sumofdigits
  

######################################################################
if __name__=='__main__':

import numpy as np
import string, random

nondigits = string.ascii_letters + ' ' + string.punctuation

DEBUG = True
#DEBUG = False #uncomment to show more screen output

repeat=200
#arvect=np.random.randn(repeat,1)
arvect=np.random.normal(10**16, 10**17, (repeat,1))
arrint=[int(x*10) for x in arvect]

TEST=[]; tsum={}; ysum={}
for i in range(len(arrint)):
if arrint[i] >= 0:
sloc=0
for j in str(arrint[i]):
sloc+=int(j) #end for j
tsum[i]=sloc
else:
sloc=0
for j in str(arrint[i])[1:]:
sloc+=int(j) #end for j
tsum[i]=-sloc #end if

s1=str(arrint[i])
s2=[s1[0]]   
for j in s1[1:]:
s2.append(j)
s2.append(random.choice(nondigits))
if i%2 == 0:
s = ' ' + ''.join(s2)
else:
s = ' -/ ' + ''.join(s2)
if tsum[i]>0: tsum[i]=-tsum[i]

if DEBUG: print('s=',s)

ysum[i]=sumDigits(s)
if tsum[i] == ysum[i]:
TEST.append(True)
else:
TEST.append(False) #end for i

if all(TEST):
print("\n Great, you passed {} tests for Problem 3!\n".format(repeat))
else:
print("\n *** {} tests failed for Problem 3. Need more debugging.\n".format(len([x for x in TEST if x==False])))

Answer 1

Please give the thumbs up, if it is helpful for you!!. Let me know if you have any doubts.

Your code will fail for sumDigits('A+3-3-4*D').

if should retrun 10 but your code is returing -10.

I have corrected the code, Please check and do let me know if it is passing all the cases.

def sumDigits(s):
r = 0
f = 1  
for i in s:
if i.isdigit():
r = r+ int(i)
if s[0] == '-':
f = -1
sumofdigits= f*r
return sumofdigits

sumDigits('A33$%4C*+D')  
sumDigits('-A+3-3-4*D')
sumDigits('A+3-3-4*D')  

Output: