Basics of Python in a nutshell!

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x = 8 y = "variable" print(x) # to print a statement print(y) a , b = "Hello" , "World" # to assign values in single line print(a) print(b) 

x = 8 print(type(x)) 

a = 4 b = 9 print(a+b) # addition print(a-b) # subtraction print(a/b) # division print(a*b) # multiplication print(a**b) # exponentiation 

a = ["Hello", "World", "!"] #List b = ("Hello", "World", "!") #Tuple c = {"Hello", "World", "!"} #Set d = {"name" : "Suraj", "age" : 18, "location": "India"} #Dict ``` * To understand the data structures in detail: 1) List: ``` #To print items in list using for loop: this_list = ["A", "B", "C"] for x in this_list: # don't forget indentation in python codes print(x) #To check if item is present in the list: this_list = ["A", "B", "C"] if "D" in this_list : print("present") #Note: You may add print statements to view your results. # Use the append() to append an item in the list: this_list = ["A", "B", "C"] this_list.append("D") #To insert item at a specified index in the list: this_list = ["A", "B", "C"] this_list.insert(1, "D") #To remove a specific item from the list: this_list = ["A", "B", "C"] this_list.remove("B") #To pop last item from the list: this_list = ["A", "B", "C"] this_list.pop() #To removes an item from a specified index this_list = ["A", "B", "C"] del this_list[1] #To clear the entire list this_list = ["A", "B", "C"] this_list .clear() #To find length of the entire list this_list = ["A", "B", "C"] len(this_list) #To join two lists this_list = ["A", "B", "C"] another_list = ["D", 3, 4] result_list = this_list + another_list # result_list would have elements from both list #To convert List to Tuple: this_list = ["A", "B", "C"] tuple(this_list ) #To slice List: this_list = ["A", "B", "C"] this_list[3:8] # slicing the list ``` 2) Tuple: ``` # To print items in Tuple: this_tuple = ("A", "B", "C") for x in this_tuple: print(x) #To find length of Tuple: this_tuple = ("A", "B", "C") print(len(this_tuple)) # Convert this_tuple = ("A", "B", "C") list(this_tuple) #converting tuple to list #To find type of Tuple: this_tuple = ("A", "B", "C") print(type(this_tuple)) # To slice Tuples this_tuple = ("A", "B", "C", "D" , "E") print(this_tuple[1:]) # to print items from index 1 # to print items starting from index 2 to index 3 (i.e 4-1) print(this_tuple[2:4]) print(this_tuple[::-1]) # to print in reverse manner #To delete a tuple this_tuple = ("A", "B", "C") del this_tuple ``` 3) Set: ``` # To print items in Set: this_set = {"A", "B", "C"} for x in thisset: print(x) #To add items in set : this_set = {"A", "B", "C"} this_set .add("D") #To update set : this_set = {"A", "B", "C"} this_set .update([1,2,3]) #To remove an item from a set: this_set = {"A", "B", "C"} this_set .remove("C") #To pop item from set this_set = {"A", "B", "C"} this_set .pop() #To clear everything from the set: this_set = {"A", "B", "C"} this_set.clear() #To add items form one set to another this_set = {"A", "B", "C"} another_set= {1, 2, 3} this_set.update(another_set) #Note: every time you run the command the items would be #shuffled which justify that items in set are unordered. #Operations in Sets: this_set = {1,2,3,4,5} another_set= {3,4,5,6,7} print(this_set|another_set) #Union print(this_set - another_set) #Difference print(this_set & another_set) #Intersection ``` 4) Dictionary: ``` #To print a Dictionary: # items are in key:value pairs this_dict = { "Name": "Suraj", "Age": "18", "Year": 2020 } print(this_dict) # You can also use a for loop. #Adding new index key with value: this_dict = {"Name": "Suraj", "Age": "18", "Year": 2020} this_dict["newItem"] = "newValue" #To pop a value from a dictionary: this_dict.pop("Year") #specifying key value #To clear the Dictionary: this_dict.clear() #To copy items from one Dictionary to another : this_dict = {"Name": "Suraj", "Age": "18", "Year": 2020} another_dict = this_dict.copy() # then print #To delete a value from Dictionary: this_dict = {"Name": "Suraj", "Age": "18", "Year": 2020} del Dict["Age"] ``` * Characters in Python : ``` character = "Hello World!" print(character[1]) # to get character at index 1 print(character[3:7]) # to get character at from index 3 to 6 #It can also be done using negative indexes #To find the length of the character len(character) #Some other basic functions: character = "Hello World!" print(character .lower()) # to convert to lowercase print(character .upper()) # to convert to uppercase print(character .replace("W", "Y")) # To replace characters in it print(character .split(",")) # returns ['Hello World!'] ``` * Logical operators in Python: <br> They are used to combine conditional statements. <br> ``` and - returns True if both statements are true . or - returns True if one of the statements is true . not - reverses the result, returns False if the result is true . ``` * Loops in Python: ``` #For loop num = 0 for num in range(0, 10): print(num) # to print numbers from the range #While loop while (num < 10): num = num + 1 print(num) # to print numbers ``` * If-else statements in Python: ``` num = 0 for num in range(0, 10): if(num<5): print(num) # to print numbers less than 5 ``` * Functions in Python: ``` def function(x): print("Function called") print("Value passed is ",x) function(5) # Now using lamda function. # It can take any number of arguments, but can only have one #expression. #syntax : lambda arguments : expression function = lambda x : x*2 print("Returning a value twice the passed value:",function(10)) ``` With this, we have slid through the basics. <br> Hope it's been helpful!