How to pick one number of an Integer

Question

How can I pick one of the digits from an Integer like: 97723 and choose (for example) the number 2 from that number and check if its an odd or an even number?

Also, can I print only the odd numbers from an Integer directly? (Is there any default function for that already?)

Thanks in advance

honestly i didn't find anything to try yet, I didn't find any function that reads an integer digit to digit — Pitipaty, Oct 05 '16 at 21:00
Sam Redway, str(97723)[3] it's what I was looking for, Thanks :) — Pitipaty, Oct 05 '16 at 21:01
str(97723)[3] is a string, so str(97723)[3] % 2 will raise an exception. — honza_p, Oct 05 '16 at 21:12
true, i can always convert the string to a digit again after selecting it tho — Pitipaty, Oct 05 '16 at 21:16

score 3 · Accepted Answer · edited Oct 05 '16 at 23:58

3

2 is the 4th digit.

You can get the digits of a number using this construct.

digits = [int(_) for _ in str(97723)]

This expression will be true if the 4th digit is even.

digits[3] % 2 == 0

edited Oct 05 '16 at 23:58

kmario23

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answered Oct 05 '16 at 21:00

Bill Bell

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This won't generalize. I think the OP is looking for a method to pick an arbitrary digit out of a number. – kmario23 Oct 05 '16 at 21:04
My objective was to offer a simple answer to a simple question. What sort of generalisation would you like? – Bill Bell Oct 05 '16 at 23:04

score 1 · Answer 2 · answered Oct 05 '16 at 21:19

# choose a digit (by index)

integer = 97723

digit_3 = str(integer)[3]

print(digit_3)

# check if even:

if int(digit_3) % 2 == 0:
    print(digit_3, "is even")


# get all odd numbers directly

odd_digits = [digit for digit in str(integer) if int(digit) % 2 == 1]

print(odd_digits)

score 0 · Answer 3 · answered Oct 05 '16 at 21:12

even = lambda integer: int("".join([num for num in str(integer) if int(num) % 2 == 0]))

or

def even(integer):
    result = ""
    integer = str(integer)
    for num in integer:
        if int(num) % 2 == 0:
            result += num
    result = int(result)
    return(result)

score 0 · Answer 4 · answered Oct 05 '16 at 21:17

If you want to "parse" a number the easiest way to do this is to convert it to string. You can convert an int to string like this s = string(500). Then use string index to get character that you want. For example if you want first character (number) then use this string_name[0], for second character (number) use string_name[1] . To get length of your string (number) use len(string). And to check if number is odd or even mod it with 2.

# Converting int to string
int_to_sting = str(97723)

# Getting number of characters in your string (in this case number)
n_of_numbers = len(int_to_sting)

# Example usage of string index
print("First number in your number is: ",int_to_sting[0])
print("Second number in your number is: ",int_to_sting[1])

# We need to check for every number, and since the first number is int_to_sting[0] and len(int_to_sting) returns actual length of string we need to reduce it by 1
for i in range(n_of_numbers-1):
        if int_to_sting[i]%2==0:
              print(int_to_sting[i]," is even")
        else:
              print(int_to_sting[i]," is odd")

How to pick one number of an Integer

4 Answers4