Numbers
Python has integers, floats and complex numbers.
Syntax
n = 42
pi = 3.14159Python has three numeric types:
- int — whole numbers of any size:
42,-7. - float — numbers with a decimal point:
3.14,9.99. - complex — numbers with an imaginary part, written with
j:2 + 3j.
Unlike many languages, Python integers never overflow — they can be as large as your memory allows.
Example
count = 42
price = 9.99
big = 1_000_000
print(count, price, big)
print(2 ** 100)
# Output:
# 42 9.99 1000000
# 1267650600228229401496703205376When to use it
- An e-commerce site calculates the total price as a float after applying a percentage discount.
- A scientific simulation uses large integers to count molecules without overflow errors.
- A graphics program converts a float pixel coordinate to an integer index for array access.
More examples
Integer and float arithmetic
Multiplying an int by a float produces a float result, which type() confirms.
items = 4
price = 2.50
total = items * price
print(type(total), total)
# Output:
# <class 'float'> 10.0Integer division and remainder
Uses floor division // and modulo % to split minutes into hours and leftover minutes.
minutes = 137
hours = minutes // 60
remaining = minutes % 60
print(f'{hours}h {remaining}m')
# Output:
# 2h 17mLarge int and scientific float
Demonstrates underscore separators in large ints and scientific notation floats.
population = 8_000_000_000 # underscore for readability
light_speed = 3e8 # scientific notation
distance = 1.5e11
travel_time = distance / light_speed
print(f'~{travel_time:.0f} seconds')
# Output:
# ~500 seconds
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