Question: 
Write a python function to count numeric values in a given string.


Model's Code:
def number_ctr(s):
    return sum(c.isdigit() for c in s)



Sample Correct Code:
def number_ctr(str):
      number_ctr= 0
      for i in range(len(str)):
          if str[i] >= '0' and str[i] <= '9': number_ctr += 1     
      return  number_ctr


Asserts:
assert number_ctr('program2bedone') == 1
assert number_ctr('3wonders') ==1
assert number_ctr('123') == 3


Tests:
Test 1 of 3: PASS
Test 2 of 3: PASS
Test 3 of 3: PASS

Test 764 of 974: 578/764 (75.6544502617801%): success