How to count how many times a number was printed using python?-CodePudding

So I made a nooby Collatz Sequence showing program. I am interested in knowing how many times number was printed by the computer so that I can see how many steps it took for a number to eventually become 1. If you don't know much about the Collatz sequence, run my code...

import sys

def collatz(number):

    if number <= 0:
        print("Next time, enter an integer greater than 1.")
        sys.exit()

    while number % 2 == 0:
        number = number // 2
        print(number)

    if number == 1:
        sys.exit()

    while number % 2 != 0:
        number = 3*number 1
        print(number)
        collatz(number)


print("Enter a number.")
print("Even number is halfed, odd number is multiplied by 3 and 1 is added to the product.")
print("This is called as Collatz sequence.")
print("Watch as your number slowly becomes 1.\nEnter a positive integer:")
try:
    collatz(int(input()))
except ValueError:
    print("Next time, Enter a positive integer, you dummy...")

CodePudding user response：

One really quick and dirty way to do this, would be to just use an "iterations" argument. Something like this would get your desired result:

import sys    
def collatz(number, iterations=0):
    
        if number <= 0:
            print("Next time, enter an integer greater than 1.")
            sys.exit()
    
        while number % 2 == 0:
            number = number // 2
            print(number)
            iterations  = 1
    
        if number == 1:
            print(f'This number took {iterations} steps to get to 1')
            sys.exit()
    
        while number % 2 != 0:
            number = 3*number 1
            print(number)
            iterations  = 1
            collatz(number, iterations)
    
    
    print("Enter a number.")
    print("Even number is halfed, odd number is multiplied by 3 and 1 is added to the product.")
    print("This is called as Collatz sequence.")
    print("Watch as your number slowly becomes 1.\nEnter a positive integer:")
    try:
        collatz(int(input()))
    except ValueError:
        print("Next time, Enter a positive integer, you dummy...")

CodePudding user response：

You can also use a global variable steps. But NewBoard's solution is also good.

import sys

steps = 0

def collatz(number):
    global steps

    if number <= 0:
        print("Next time, enter an integer greater than 1.")
        sys.exit()

    while number % 2 == 0:
        steps  = 1
        number = number // 2
        print(number)

    if number == 1:
        print(f"Steps: {steps}")
        sys.exit()

    while number % 2 != 0:
        steps  = 1
        number = 3*number 1
        print(number)
        collatz(number)


print("Enter a number.")
print("Even number is halfed, odd number is multiplied by 3 and 1 is added to the product.")
print("This is called as Collatz sequence.")
print("Watch as your number slowly becomes 1.\nEnter a positive integer:")
try:
    collatz(int(input()))
except ValueError:
    print("Next time, Enter a positive integer, you dummy...")