Python · Theory

Python Modules

Theory

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Python Modules

A module is a .py file you import and reuse. import math then math.sqrt(9) is 3.0. from math import sqrt lets you call sqrt(9) directly. Your own utils.py can be a module if it sits on the path. A package is a folder of modules (often with __init__.py).

import math brings the whole module namespace. from math import sqrt brings one name. If two modules have sqrt, import module keeps them apart: math.sqrt vs other.sqrt. Don’t star-import in real code.

Python Modules — output — 7.0 then 3.14159…. math is a real stdlib module.

Exam tip

import vs from-import difference.

Example

# Modules
import math
print(math.sqrt(49))
print(math.pi)

Python Modules — output: 7.0 then 3.14159…. math is a real stdlib module.

Short notes

Def.py file you import.
Ruleimport x vs from x import y.
RememberYour file can be a module.

Python · Theory

Python Modules

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Theory

46/268

Python Modules

Python Modules — output — 7.0 then 3.14159…. math is a real stdlib module.

Exam tip

import vs from-import difference.

Example

# Modules
import math
print(math.sqrt(49))
print(math.pi)

Python Modules — output: 7.0 then 3.14159…. math is a real stdlib module.

Short notes

Def.py file you import.
Ruleimport x vs from x import y.
RememberYour file can be a module.

Python Modules

Example

Short notes

Questions

Python Modules

Example

Short notes

Questions