python : Collatz Sequence

Question

I am a beginner in python. I found this problem in the book Automate the Boring Stuff with Python. How can I improve this program using latest version of python.

def generateCollatzSequence(number):
 print(str(number) + " ")
 while number != 1:
 if number % 2 == 0:
 number = number / 2
 print(str(number) + " ")
 elif number % 2 == 1:
 number = (3 * number) + 1
 print(str(number) + " ")
#print("Enter number: ")
inputNumber = int(input("Enter number: "))
generateCollatzSequence(inputNumber)

• Martin R: Have a look at codereview.stackexchange.com/q/205785/35991, codereview.stackexchange.com/q/194837/35991, and codereview.stackexchange.com/q/221741/35991 for quite similar questions.

Answer 1

• Your function is called generate but it doesn't return anything. Instead display would be a better name.
• It would be better if you had two functions one to generate the values, one to display them.
• Function names should be lower_snake_case to be idiomatic.
• + " " is not needed, as print makes the value go to the next line anyway.
• str(number) also isn't needed as print will do this automatically for you.

Thanks @Toby Speight:

• You can move the print to be after both the if and the else.

def generate_collatz_sequence(number):
 output = [number]
 while number != 1:
 if number % 2 == 0:
 number = number / 2
 elif number % 2 == 1:
 number = (3 * number) + 1
 output.append(number)
def display_collatz_sequence(values):
 for number in values:
 print(number)

If you want this to still display values in real time, then you can make generate_collatz_sequence a generator function.

def generate_collatz_sequence(number):
 yield number
 while number != 1:
 if number % 2 == 0:
 number = number / 2
 elif number % 2 == 1:
 number = (3 * number) + 1
 yield number