How to reset counter in Python

Question

Hi I'm new to programming, i have a program that will count name start from 1 to the range of a data. My problem is the counter will continue to add the previous name. For example, when i run file 1 , it will show a,b,c , but when i run the second file the name will start from d,e,f. What i want is to reset the counter value to A whenever i choose a new file.

My code

num = 0
def countname():
    global num
    num += 1
    return str(num)

def change():
  for content in data2:
     filename = "" + "Name" + " " + countname()
     print(filename)

This sounds like a job for `enumerate`, not for a global counter. — user2357112, Mar 19 '21 at 05:55
Documentation: [enumerate](https://docs.python.org/3/library/functions.html?highlight=enumerate#enumerate) — Mark Tolonen, Mar 19 '21 at 06:00
That's mean not the code issues but is my logic problem right? — Jackson Lim, Mar 19 '21 at 06:01

Patrick Artner · Accepted Answer · 2021-03-19T10:26:21.377

Your problem is somewhere else in your code - not in the shown parts - they work:

num = 0
def countname():
    global num
    num += 1
    return str(num)

def change(data2):
    for content in data2:  
        filename = "" + "Name" + " " + countname()
        print(filename)

# the content (a,b, etc. is currently ignored)
change ("a b c d e f".split())

Output:

Name 1  
Name 2
Name 3
Name 4
Name 5
Name 6

A better version without global would be:

def change_better(data2):
    # start indexing at 1 and loop over index,datapoints
    for index, content in enumerate(data2, 1):
        filename = f"Name {index}"
        print(filename)

change_better ("a b c d e f".split())

wich genenerates the same output as above.

Your code is not a minimal reproduceable example that replicates your problem, the source of your observed error is elsewhere.

My hunch would be that you somewhere add this created filename to some other thing (f.e. a path) and you use that to create the file. And there is the problem with repeating names.

See String formatting: % vs. .format vs. string literal for f-style string literal formatting

How to reset counter in Python

1 Answers1