Module 10: Quick Reference

Import Styles

import math                     # Full module: math.sqrt(16)
from math import sqrt, pi       # Specific items: sqrt(16)
import math as m                # Alias: m.sqrt(16)
from math import sqrt as sr    # Function alias: sr(16)

math Module

Function/Constant	Description	Example
math.sqrt(x)	Square root	math.sqrt(25) → 5.0
math.ceil(x)	Round up	math.ceil(3.2) → 4
math.floor(x)	Round down	math.floor(3.9) → 3
math.pi	Pi constant	3.141592653589793
math.pow(x, y)	x raised to y	math.pow(2, 3) → 8.0
math.fabs(x)	Absolute value (float)	math.fabs(-5) → 5.0

random Module

Function	Description	Example
random.randint(a, b)	Random int from a to b (inclusive)	randint(1, 6) → 4
random.choice(seq)	Random item from sequence	choice(["a","b"]) → "b"
random.shuffle(list)	Shuffle list in place	Returns None, modifies list
random.sample(seq, k)	k unique random items	sample([1,2,3], 2) → [3,1]
random.random()	Random float 0.0 to 1.0	0.7234...

datetime Module

from datetime import datetime
now = datetime.now()
now.year, now.month, now.day, now.hour, now.minute

Format Code	Meaning	Example
%Y	4-digit year	2025
%m	Month (01-12)	06
%d	Day (01-31)	15
%B	Full month name	June
%A	Full weekday	Sunday
%I	12-hour clock	02
%H	24-hour clock	14
%M	Minute	30
%p	AM/PM	PM

pip Commands (Terminal)

pip install package_name         # Install a package
pip install package==1.0.0       # Install specific version
pip install --upgrade package    # Upgrade a package
pip uninstall package            # Remove a package
pip list                         # List installed packages
pip freeze > requirements.txt    # Save package list
pip install -r requirements.txt  # Install from file

Module Best Practices

# Use __name__ guard for test code
if __name__ == "__main__":
    # This only runs when file is executed directly
    print("Testing...")

# Import order: stdlib → third-party → your modules
# Place all imports at the top of the file
# Avoid: from module import *