Python Interview Questions
Modules, packages, the import system, pip, and the script-vs-import execution guard.
Ans
A module is a Python file containing definitions and executable statements that can be imported by other code.
Example
python# math_utils.py def add(a, b): return a + b # another file from math_utils import add print(add(2, 3))
Important Point
Keep module-level side effects small; use an `if __name__ == "__main__"` guard for script-only execution.
Ans
A package is a structured collection of Python modules, normally represented by directories and importable package namespaces.
Example
textshop/ __init__.py orders.py users.py
Important Point
Modern Python can support namespace packages without an `__init__.py`, but regular packages commonly include one.
Ans
When a Python file is run directly, its __name__ is set to __main__. When imported, its __name__ is the module name. The guard separates script execution from importable definitions.
Example
pythondef main(): print("Running app") if __name__ == "__main__": main()
Important Point
This prevents the guarded code from running merely because another module imports the file.
Ans
pip is the standard package installer commonly used to install Python packages from package indexes and other sources.
Example
bashpython -m pip install requests
Important Point
Using `python -m pip` helps ensure pip belongs to the intended Python interpreter/environment.
Ans
A virtual environment isolates a project's Python interpreter context and installed packages from other projects.
Example
bashpython -m venv .venv # activate it according to the operating system python -m pip install requests
Important Point
Create separate environments for projects with different dependency requirements.
Ans
A requirements file records project dependencies so another environment can install compatible packages with pip.
Example
textrequests==2.32.3 pytest==8.3.2
Important Point
Pinning every dependency can improve reproducibility, but teams may use modern dependency-management tools instead.
Ans
import loads a module and binds a module name in the importing namespace. from module import name binds a specific attribute directly.
Example
pythonimport math print(math.sqrt(25))
Important Point
Circular imports can cause partially initialized modules; organize dependencies to avoid unnecessary cycles.
Ans
A circular import occurs when module A imports B while B directly or indirectly imports A. It can produce partially initialized modules and import errors.
Example
textA -> imports B B -> imports A
Important Point
Move shared definitions into a third module or redesign dependencies rather than relying on import timing tricks.
Ans
__all__ defines names intended for wildcard imports such as from module import *. It also documents a module's public export list for that use case.
Example
python__all__ = ["add", "multiply"]
Important Point
Explicit imports are usually clearer than wildcard imports.