Common Python Standard and Third‑Party Libraries with Usage Examples

The article presents a collection of frequently used Python standard libraries—including datetime , zlib , random , math , sys , glob , and os —and describes each library's main purpose.

It also lists common third‑party libraries such as Scrapy , Requests , Pillow , matplotlib , OpenCV , pytesseract , wxPython , Twisted , SymPy , SQLAlchemy , SciPy , NumPy , nose , nltk , IPython , and BeautifulSoup , briefly noting their typical use cases.

Below are practical usage examples for several standard modules.

datetime module example:

from datetime import date
# import time library
now = date.today()
print(now)
birthday = date(1987, 12, 3)
print(birthday)
age = now - birthday
print(age)

Running this code prints the current date, a specific birthday, and the calculated age in days.

zlib module example:

import zlib
m = b'This is a test compress'
print(m)
m1 = len(m)
print(m1)
t = zlib.compress(m)
t1 = len(t)
print(t)
print(t1)
s = zlib.decompress(t)
print(s)

This snippet demonstrates compressing a byte string, checking lengths before and after compression, and then decompressing back to the original data.

sys module example:

import sys
a = sys.path
print(a)

The code prints the list of directories that Python searches for modules, showing the current environment's import paths.