Advanced-Python-Concepts

1. Lists

• A collection datatype

• ordered

• mutable

• can have different data types

• allows duplicate elements

  myList = ["apple", "dog", 5, True]
  myList2 = list()         # []
  
  item = myList[0]         # index must be less than n
  item2 = myList[-1].      # last item, -2 for second last item
  
  for x in myList:
  	print(x)
  
  if "dog" in myList:
  	print("yes")
  	
  n = len(myList)
  
  myList.append("lemon")
  myList.insert(1, "banana")   # insert banana at index 1
  lastElement = myList.pop()   # .pop() returns the last item and also removes it
  myList.remove("apple")      # to remove an element by value, if its not present you will get a ValueError, so be careful
  myList.clear()              # remove all elements
  myList.reverse().           # reverses in place
  
  myList.sort()

refer to this git repo: https://github.com/Yash-op7/Advanced-Python-Concepts

The topics that I learnt are:

• Lists.py
  • list()
  • len()
  • append()
  • pop()
  • insert()
  • clear()
  • remove()
  • reverse()
  • sort()
  • sorted()
  • list1 = [0] * 5
  • concatenation of two lists with the + operator
  • list slicing
  • copying, deep copy → 3 ways
    • oldList.copy()
    • newlist = oldList[:]
    • newList = list(oldList)
  • list comprehension - 10 examples - must revise them
  • set comprehension
  • dict comprehension
• important_python_concepts.py
  • mutable v/s immutable types in python
  • positional arguements in functions, defautl arguements, *args and **kwargs and dynamic variable unpacking or reverse args and kwargs
  • meaning of __name__ == "__main__"
  • meaning of GLI or Global Interpreter Lock and cpu cores and multithreading in python
• important_python_functions.py
  • print()
  • help()
  • range()
  • map()
  • lambda functions
  • filter()
  • sum()
  • sorted()
  • enumerate()
  • zip()
  • open()
• generators_vs_iterators.py
  • what are iterators
  • iter() or .__iter__() method
  • next() method
  • creating your own iterators with legacy syntax
  • creatign genreators with modern syntax
  • generator use cases
• important tips in general:
  • items = [chr(ord('a')+i) for i in range(6)] → items is ['a', 'b', 'c', 'd', 'e', 'f'] (ASCII manipulation)
• hidden_python_features.py
  • while-else loop and for-else loop to identify whether a loop broke early or not
  • Anonymous variables for better readability
  • := walrus operator
  • defaultdict