CODEWITHSUNDEEP
python
nedarb
nedarb

Reputation: 35

Python - Convert 8 bit binary number to decimal

import math

while True:
    try:
        user_bin = int(input('\nPlease enter binary number: '), 2)
    except ValueError:
        print('Please make sure your number contains digits 0-1 only.')
    else:
        print(user_bin)

I've just been browsing this site looking for tips on how to complete an assignment, the basics of the assignment is to have the user input an 8 bit binary number, and convert it to decimal. Or pop up an invalid input error in situations where it doesn't fit the requirements. The code above seemed interesting so I tested it and I genuinely don't understand which part of the code converts the binary to decimal. Any tips for the assignment as well as explanations would be appreciated.

Upvotes: 0

Views: 2031

Answers (1)

Calum You
Calum You

Reputation: 15062

The part that converts the binary is int. From the documentation:

if base is given, then x must be a string, bytes, or bytearray instance representing an integer literal in radix base.

This means that int accepts a string representing an integer, that you tell it the base of. E.g. here we give it "11", and tell it this is in base 2, so it returns the integer 3 in decimal.

>>> int("11", 2)
3

Note that when supplying the base argument, you have to give a string:

>>> int(11, 2)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: int() can't convert non-string with explicit base

And you can't use digits that are invalid in the given base:

>>> int("21", 2)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: invalid literal for int() with base 2: '21'

Upvotes: 4

Related Questions