Python Numbers

Numeric Types in Python

In Python, there are three distinct numeric types:

  • Integers
  • Floating-point numbers
  • Complex numbers
Python Numbers - Integers, Floats, Complex Numbers

Integers

An integer is a whole number that can be positive or negative.

Example: Following numbers are integers

x = 10
y = -10
z = 123456789

In Python 3, there is no limit to how long an integer value can be.

It can grow to have as many digits as your computer’s memory space allows.

Example: Integers have unlimited precision

x = 99999999999999999999999999999999999999999999999999999999999999999999999999999999

We normally write integers in base 10.

However, Python allows us to write integers in Hexadecimal (base 16), Octal (base 8), and Binary (base 2) formats.

You can do that by adding one of the following prefixes to the integer.

Prefixes for binary, octal & hex formats
PrefixInterpretationBase
‘0b’ or ‘0B’Binary2
‘0o’ or ‘0O’Octal8
‘0x’ or ‘0X’Hexadecimal16

Example: Integers in binary, octal and hexadecimal formats

# binary
print(0b10111011)	# 187
# octal
print(0o10)			# 8
# hex
print(0xFF)			# 255

In addition, Boolean is a sub-type of integers.

Example: Boolean in python

x = True
x = False

Floating-Point Numbers

Floating-point number or Float is a positive or negative number with a fractional part.

Example: Following numbers are floats

x = 10.1
y = -10.5
z = 1.123456

You can append the character e or E followed by a positive or negative integer to specify scientific notation.

Example: Scientific notation

print(42e3)    # 42000.0

print(4.2e-3)   # 0.0042

The maximum value a float can have is approximately 1.8×10308

Any number greater than that is indicated by the string inf (infinity)

Example: Maximum value of a float

print(1.79e308)	# 1.79e+308

print(1.8e308)	# inf

However, the minimum value a float can have is approximately 5.0×10-324

Any number, less than that is considered zero.

Example: Minimum value of a float

print(5e-324)	# 4.94065645841e-324

print(5e-325)	# 0.0

Complex Numbers

A complex number is specified as real_part + imaginary_part, where the imaginary_part is written with a j or J.

Example: Following numbers are complex numbers

x = 2j
y = 3+4j

To extract real and imaginary parts from a complex number x, use x.real and x.imag

Example: Extract real and imaginary parts from a complex number

x = 3+4j

print(x.real) # 3.0

print(x.imag)  # 4.0