Advanced Topics on Integer and Float

Integer Methods

1- int.bit_length()

Returns the number of bits necessary to represent an integer in binary, excluding the sign and leading zeros.

Example:

num = -37
print(bin(num))  # Output: '-0b100101'
print(num.bit_length())  # Output: 6

Details:

• For a nonzero integer x, x.bit_length() returns the unique positive integer k such that 2**(k-1) <= abs(x) < 2**k.
• For zero, it returns 0.

Equivalent to:

def bit_length(num: int) -> int:
    num_strip = bin(num).lstrip('-0b')  # Remove leading zeros and minus sign
    return len(num_strip)

2- int.bit_count()

Returns the number of 1s in the binary representation of the absolute value of the integer (also known as the population count).

Example:

num = 19
print(bin(num))  # Output: '0b10011'
print(num.bit_count())  # Output: 3

Equivalent to:

def bit_count(num: int) -> int:
    return bin(num).count("1")

3- int.to_bytes(length, byteorder, *, signed=False)

Converts an integer to an array of bytes.

Example:

print((1024).to_bytes(2, byteorder='big'))  # Output: b'\x04\x00'
print((-1024).to_bytes(10, byteorder='big', signed=True))  # Output: b'\xff\xff\xff\xff\xff\xff\xff\xff\xfc\x00'

Parameters:

• length: Number of bytes.
• byteorder: 'big' or 'little'.
• signed: Whether to use two’s complement representation for negative numbers (default is False).

4- int.from_bytes(bytes, byteorder, *, signed=False)

Converts a bytes object to an integer.

Example:

print(int.from_bytes(b'\x00\x10', byteorder='big'))  # Output: 16
print(int.from_bytes(b'\xfc\x00', byteorder='big', signed=True))  # Output: -1024

Parameters:

• bytes: Bytes-like object or iterable producing bytes.
• byteorder: 'big' or 'little'.
• signed: Whether to interpret the integer as signed.

5- int.as_integer_ratio()

Returns a tuple (numerator, denominator) such that the ratio equals the integer.

Example:

print((5).as_integer_ratio())  # Output: (5, 1)

6- int.is_integer()

Returns True for integer instances.

Example:

print((5).is_integer())  # Output: True

Float Methods

1- float.as_integer_ratio()

Returns a tuple (numerator, denominator) whose ratio equals the float.

Example:

print((3.5).as_integer_ratio())  # Output: (7, 2)

2- float.is_integer()

Returns True if the float has an integral value, False otherwise.

Example:

print((-2.0).is_integer())  # Output: True
print((3.2).is_integer())  # Output: False

3- float.hex() and float.fromhex(s)

Converts a float to and from a hexadecimal string representation.

Example:

print((3740.0).hex())  # Output: '0x1.d380000000000p+11'
print(float.fromhex('0x3.a7p10'))  # Output: 3740.0

Reference:

Python Documentation

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