Python int to binary

To convert an integer to a binary string in Python, use the built-in bin() function. It returns a string prefixed with '0b' to indicate binary format.

num = 10
binary = bin(num)
print(binary)  # Output: '0b1010'

To remove the '0b' prefix, use string slicing:

binary_no_prefix = bin(num)[2:]
print(binary_no_prefix)  # Output: '1010'

For more control over formatting (like padding with leading zeros), use format() or f-strings:

# Using format()
binary_padded = format(num, '08b')  # 8-bit binary with leading zeros
print(binary_padded)  # Output: '00001010'

# Using f-strings
binary_padded = f'{num:08b}'
print(binary_padded)  # Output: '00001010'

Note: bin() works only with integers. For negative numbers, Python uses two's complement notation, so the output includes a negative sign (e.g., -0b1010 for -10).

Convert int to binary string in Python

stackoverflow.com › questions › 699866 › convert-int-to-binary-string-in-python

Python's string format method can take a format spec.

>>> "{0:b}".format(37)
'100101'

Format spec docs for Python 2

Format spec docs for Python 3

Answer from Tung Nguyen on Stack Overflow

GeeksforGeeks

geeksforgeeks.org › python › python-binary-list-to-integer

Python - Binary list to integer - GeeksforGeeks

July 11, 2025 - This is the most efficient method. By joining the binary list into a string and using the built-in int() function with a base of 2, we can directly convert the binary representation into its integer equivalent.

Stack Overflow

stackoverflow.com › questions › 699866 › convert-int-to-binary-string-in-python

Convert int to binary string in Python - Stack Overflow

Top answer

1 of 16

1115

Python's string format method can take a format spec.

>>> "{0:b}".format(37)
'100101'

Format spec docs for Python 2

Format spec docs for Python 3

2 of 16

673

If you're looking for bin() as an equivalent to hex(), it was added in python 2.6.

Example:

>>> bin(10)
'0b1010'

Discussions

How to convert an integer into a binary number without the specific function?

The idea is to repeatedly divide your number by 2, keeping track of the remainder each time, eg. def to_binary(n): assert n >= 0, 'Must be positive' binary = '' while n: # while n is not 0 n, r = divmod(n, 2) # the same as: n, r = n//2, n%2 binary = str(r) + binary # prepend the remainder to the output return binary or '0' # if the string is still empty, n must have been 0 More on reddit.com

r/learnpython

September 6, 2021

python - Convert base-2 binary number string to int - Stack Overflow

I'd simply like to convert a base-2 binary number string into an int, something like this: >>> '11111111'.fromBinaryToInt() 255 Is there a way to do this in Python? More on stackoverflow.com

stackoverflow.com

Converting integer to binary in Python - Stack Overflow

Explore Stack Internal ... Sign up to request clarification or add additional context in comments. ... The first 0 means the 0th argument to format. After the colon is the formatting, the second 0 means zero fill to 8 spaces and b for binary 2012-05-02T09:39:58.167Z+00:00 ... @Aif: Also, have a look at the standard documentation docs.python... More on stackoverflow.com

stackoverflow.com

I have a byte, I want to extract the bits (from MSB to LSB). What is the 'Python' way to do this (use a bytearray)?

I would use something like the following, but I'm not sure python is the best language for doing this sort of bit manipulation in. There are some C-based libraries that implement this you could look at.

output = [input & 1<<x > 0 for x in range(input.bit_length())]

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