Question: 
Write a python function to count the upper case characters in a given string.


Model's Code:
def upper_ctr(s):
    return sum(1 for char in s if char.isupper())



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


Asserts:
assert upper_ctr('PYthon') == 1
assert upper_ctr('BigData') == 1
assert upper_ctr('program') == 0


Tests:
Test 1 of 3: FAIL: AssertionError()

Test 461 of 974: 337/461 (73.10195227765726%): failed