Why does my python input function asks for input twice?

Question

Basically you choose how many lines, then it prints random numbers to file. The program works but I need to input the number twice.

import random
import datetime

def getInput():

    try:
        user = int(input("How many lines? "))
        if user > 14:
            print("Max 14!")
            getInput()
        else:
            return user
    except ValueError:
        print("Numbers Only!")
        getInput()

def go(user):

    now = datetime.datetime.now()
    num = 0
    f = 'C:/Users/Gilush/Desktop/lot.txt'
    with open(f,'a') as file:
        file.write(f'{now.strftime("%d.%m.%y")}\n\n')
        while num < user:
            rand = random.sample(range(1,37), 6)
            rand.sort()
            s = random.sample(range(1,8), 1)
            file.write(f'{rand},{s}\n')
            num += 1
        file.write('======\n')
        file.close()

getInput()
go(user=getInput())

Remember - `getInput` needs to return a value on all paths. Change those internal calls to `return getInput()` or the input will be lost. — tdelaney, May 22 '20 at 20:02
Does this answer your question? [Asking the user for input until they give a valid response](https://stackoverflow.com/questions/23294658/asking-the-user-for-input-until-they-give-a-valid-response). You're trying to validate an acceptable input and doing in incorrectly. The duplicate shows how to do this. — Trenton McKinney, May 22 '20 at 20:03
@tdelaney can you show me an example? I got lost trying to fix that issue as well. Thank you! — Gilush, May 22 '20 at 20:11
I've posted a full working fix. Mine is just an FYI, the first answer is the official answer to your question. — tdelaney, May 22 '20 at 20:19

score 3 · Accepted Answer · answered May 22 '20 at 20:00

3

getInput()
go(user=getInput())

This calls getInput twice. One time on each line.

You probably want:

user = getInput()
go(user)

answered May 22 '20 at 20:00

Thomas

4,208
2
29
31

score 1 · Answer 2 · answered May 22 '20 at 19:59

1

getInput()
go(user=getInput())

do you see you are calling getInput twice

maybe you want to do

user = getInput()
go(user)

# or
# go(user = getInput())

answered May 22 '20 at 19:59

ashish singh

6,526
2
15
35

score 0 · Answer 3 · answered May 22 '20 at 20:15

0

Use user to take getInput() and go the value in user as go(user)

answered May 22 '20 at 20:15

Pankaj Garg

1
2

score 0 · Answer 4 · answered May 22 '20 at 20:18

As mentioned in other answers, you've called getInput twice. There was a second issue about propegating getInput results back to the original caller. Here is the script with both fixes.

import random
import datetime

def getInput():

    try:
        user = int(input("How many lines? "))
        if user > 14:
            print("Max 14!")
            return getInput()
        else:
            return user
    except ValueError:
        print("Numbers Only!")
        return getInput()

def go(user):

    now = datetime.datetime.now()
    num = 0
    # todo: removed for test
    # f = 'C:/Users/Gilush/Desktop/lot.txt'
    f = 'lot.txt'
    with open(f,'a') as file:
        file.write(f'{now.strftime("%d.%m.%y")}\n\n')
        while num < user:
            rand = random.sample(range(1,37), 6)
            rand.sort()
            s = random.sample(range(1,8), 1)
            file.write(f'{rand},{s}\n')
            num += 1
        file.write('======\n')
        file.close()

user = getInput()
go(user=user)

score 0 · Answer 5 · answered May 22 '20 at 20:19

Rewrite `getInput` and add `def main()`

`getInput`

def getInput():
    while True:
        try:
            user = int(input("How many lines? "))
        except ValueError:
            print("Numbers Only!")
            continue
        if user > 14:
            print("Max 14!")
            continue
        else:
            return user

`def main()`

def main():
    user_input = getInput()
    go(user_input)

full program

def getInput():
    while True:
        try:
            user = int(input("How many lines? "))
        except ValueError:
            print("Numbers Only!")
            continue
        if user > 14:
            print("Max 14!")
            continue
        else:
            return user


def go(user):

    now = datetime.datetime.now()
    num = 0
    f = 'C:/Users/Gilush/Desktop/lot.txt'
    with open(f,'a') as file:
        file.write(f'{now.strftime("%d.%m.%y")}\n\n')
        while num < user:
            rand = random.sample(range(1,37), 6)
            rand.sort()
            s = random.sample(range(1,8), 1)
            file.write(f'{rand},{s}\n')
            num += 1
        file.write('======\n')
        file.close()


def main():
    user_input = getInput()
    go(user_input)


main()

Why does my python input function asks for input twice?

5 Answers5

Rewrite getInput and add def main()

getInput

def main()

full program

Rewrite `getInput` and add `def main()`

`getInput`

`def main()`