/learn-py

Primary LanguagePython

Notes

  • venv helps you install modules and packages w/o polluting the global

  • if name == 'main': this is the entry point when the code is run

  • variable names are snake_cased

  • None signifies null

  • REPL methods

    • help(): helps with documentation, like help(int)
    • type(): returns type of variable
    • dir(): show the available methods on argument, like dir(str)

  • Math operations

    • / float division
    • // integer division
    • ** raised to the power

  • Strings

    • """ for multi-line strings
    • \n new line
    • \t tab space

  • List

    • []`` or list()`
    • insert, append, reverse, sort, pop (it can take index)
    • in operator

  • Tuple

    • immutable and maintains order
    • (1,2,3,4,"Shihab")
    • empty Tuple with single entry is created as (1,)

  • Set

    • collection of unique immutable items
    • but the set itself is mutable
    • things that can be hashed are immutable
    • so sets can't have a dict or list in it
    • {"Shihab","Shana",1}
    • empty set is created as set()
    • .add(x) to insert
    • .discard(x) to remove
    • there is no guaranty that things will appear in the same order as inserted

  • from pprint import pprint

  • def print_info(name,state,country,gender):
    print(f"{name} is a {gender} from {state} in {country}")

# named arguments
print_info(gender="male",country="India",name="Shihab",state="Kerala")

names=[]
if names:
  print("Names are available)
else:
  print("Names is empty)

pip freeze > requirement.txt pip install -r requirement.txt