循环内的调用函数在 python 中不起作用

Question

That function works fine inside the loop

import random


def hello():
    count = 0
    while count < 5:
        count = count + 1
        print(str(count + random.randint(1, 30)) + " hello I am inside")
        break


count = 0
while count < 5:
    count = count + 1
    print(str(count) + " Outside")
    hello()

Print Ourput:

K:\Project\Python\Campaign\venv\Scripts\python.exe K:/Project/Python/Campaign/functionInsideLoop.py
1 Outside
12 hello I am inside
2 Outside
30 hello I am inside
3 Outside
19 hello I am inside
4 Outside
6 hello I am inside
5 Outside
23 hello I am inside

Process finished with exit code 0

But when I try to run it function didn't call repeatedly. I want to output 1 hello I am inside and increment 1, 2, 3, 4, 5

def hello():
    count = 0
    while count < 5:
        count = count + 1
        print(str(count) + " hello I am inside")
        break


count = 0
while count < 5:
    count = count + 1
    print(str(count) + " Outside")
    hello()

Print Ourput:

K:\Project\Python\Campaign\venv\Scripts\python.exe K:/Project/Python/Campaign/functionInsideLoop.py
1 Outside
1 hello I am inside
2 Outside
1 hello I am inside
3 Outside
1 hello I am inside
4 Outside
1 hello I am inside
5 Outside
1 hello I am inside

Process finished with exit code 0

The idea is calling a function inside a loop again and again. I find when I use break inside the loop the function and call it outside another loop the function didn't change.

If I give you a real example:

import sqlite3

connection = sqlite3.connect('../miracle.db')
cursor = connection.cursor()
cursor.execute("SELECT* FROM all_fb_user")


def remove_duplicate():
    records = cursor.fetchall()
    for record in records:
        singleRecord = record
        # Find All Duplicate
        cursor.execute("SELECT * FROM all_fb_user GROUP BY user_url HAVING COUNT(*) > 1;")
        records = cursor.fetchall()
        try:
            for pk in records[1]:
                duplicate_pk = (records[1])[4]
                print(duplicate_pk)
                cursor.execute("DELETE FROM all_fb_user WHERE PK=?", (duplicate_pk,))
                break
            break
        except:
            print(" There are no Duplicate in the list")
            break


count = 0
while count < 10:
    count = count + 1
    print(count)
    remove_duplicate()

connection.commit()
connection.close()

That remove_duplicate() find and remove duplicate entry because of break it stops inside the loop. I new to run this function every iteration. I need to call the function again and for removing all duplicates.

The code has no error, Logically I am making mistake. that is the request to for help.

Answer 1

The break statement is causing your code to leave the while loop. Removing the break will fix your problem

import random


def hello():
    count = 0
    while count < 5:
        count = count + 1
        print(str(count) + " hello I am inside")


count = 0
while count < 5:
    count = count + 1
    print(str(count) + " Outside")
    hello()

The above code when I remove the break statement should output

1 Outside
1 hello I am inside
2 hello I am inside
3 hello I am inside
4 hello I am inside
5 hello I am inside
2 Outside
1 hello I am inside
2 hello I am inside
3 hello I am inside
4 hello I am inside
5 hello I am inside
3 Outside
1 hello I am inside
2 hello I am inside
3 hello I am inside
4 hello I am inside
5 hello I am inside
4 Outside
1 hello I am inside
2 hello I am inside
3 hello I am inside
4 hello I am inside
5 hello I am inside
5 Outside
1 hello I am inside
2 hello I am inside
3 hello I am inside
4 hello I am inside
5 hello I am inside

Is this what you are looking for?

Answer 2

break inside hello() causing the problem, remove it, it will work as below.

>>> def hello():
...     count = 0
...     while count < 5:
...         count = count + 1
...         print(str(count) + " hello I am inside")
... 
>>> hello()
1 hello I am inside
2 hello I am inside
3 hello I am inside
4 hello I am inside
5 hello I am inside

And modify second one as below:

>>> count = 0
>>> while count < 5:
...     count = count + 1
...     print(str(count) + " Outside")
...     if count == 1:
...         hello()
...     else:
...         break
... 
1 Outside
1 hello I am inside
2 hello I am inside
3 hello I am inside
4 hello I am inside
5 hello I am inside
2 Outside
>>> 

Answer 3

I find the solution: you have to pass the parameter inside the function. in my case records .

import sqlite3

connection = sqlite3.connect('../miracle.db')
cursor = connection.cursor()
cursor.execute("SELECT* FROM all_fb_user")


def remove_duplicate(records):
    print(count)
    for record in records:
        singleRecord = record
        # Find All Duplicate
        cursor.execute("SELECT * FROM all_fb_user GROUP BY user_url HAVING COUNT(*) > 1;")
        records = cursor.fetchall()
        try:
            for pk in records[1]:
                duplicate_pk = (records[1])[4]
                print(duplicate_pk)
                cursor.execute("DELETE FROM all_fb_user WHERE PK=?", (duplicate_pk,))
                break
            break
        except:
            print(" There are no Duplicate in the list")
            break


count = 0
records = cursor.fetchall()
while count < len(records):
    count = count + 1
    remove_duplicate(records)
    print('count')

connection.commit()
connection.close()