By default the Python language providers in-built function to display alphabets letters. You can see the code here,

Create a new file named it as alphabets.py, copy the code and paste it to that file, then save it. 

def upperCaseAlphabets():
    print("Upper Case Alphabets")
    for i in range(65, 91):
        print(chr(i), end=" ")
    print()

def lowerCaseAlphabets():
    print("Lower Case Alphabets")
    for i in range(97, 123):
        print(chr(i), end=" ")

upperCaseAlphabets();
lowerCaseAlphabets();


Execute the command below then you see the outputs,


$ python alphabets.py

Upper Case Alphabets
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 
Lower Case Alphabets
a b c d e f g h i j k l m n o p q r s t u v w x y z