if __name__=='__main__':
    print('1'+'2')
    x = 5
    y = "John"
    print(x)  #5
    print(y)  #John
    print("-------------------1-----------------------")
    x = 4 # x is of type int
    x = "Sally" # x is now of type str   //TypeError: unsupported operand type(s) for //: 'NoneType' and 'int'
    print(x)
    print("-------------------2-----------------------")
    x = "awesome"
    print("Python is " + x)
    print("-------------------3-----------------------")
    x = "Python is "
    y = "awesome"
    z =  x + y
    print(z)
    print("-------------------4-----------------------")
    x = 5
    y = 10
    print(x + y)
    print("--------------------5----------------------")
    x = 5
    y = "John"
    #print(x + y)#TypeError: unsupported operand type(s) for +: 'int' and 'str'
    print("--------------------6----------------------")
    x = 1    # int
    y = 2.8  # float
    z = 1j   # complex
    print(type(x))
    print(type(y))
    print(type(z))
    print("--------------------7---------------------")
    x = 1
    y = 35656222554887711
    z = -3255522
    print(type(x))
    print(type(y))
    print(type(z))
    print("--------------------8----------------------")
    x = 1.10
    y = 1.0
    z = -35.59
    print(type(x))
    print(type(y))
    print(type(z))
    print("--------------------9----------------------")
    x = 35e3
    y = 12E4
    z = -87.7e100
    print(type(x))
    print(type(y))
    print(type(z))
    print("--------------------10----------------------")
    x = 3+5j
    y = 5j
    z = -5j
    print(x); print(type(x))
    print(y); print(type(y))
    print(z); print(type(z))
    print("--------------------11----------------------")
    x = int(1)   # x will be 1
    y = int(2.8) # y will be 2
    z = int("3") # z will be 3
    x = float(1)     # x will be 1.0
    y = float(2.8)   # y will be 2.8
    z = float("3")   # z will be 3.0
    w = float("4.2") # w will be 4.2
    x = str("s1") # x will be 's1'
    y = str(2)    # y will be '2'
    z = str(3.0)  # z will be '3.0'
    print("--------------------12----------------------")
    a = "Hello, World!"
    print(a[1])
    b = "Hello, World!"
    print(b[2:5])
    a = " Hello, World! "
    print(a.strip())  # returns "Hello, World!"
    print(len(a))
    print(a.lower())
    print(a.upper())
    print(a.replace("H", "J"))
    print(a.split(","))  # returns ['Hello', ' World!']
    print("--------------------13----------------------")
    print('--------------------14operator------------------')
    answer = 1+1
    print('1+1='+ str(answer))
    answer = 50 - 5*6
    print('50 - 5*6='+ str(answer))
    answer = 8 / 5
    print('8 / 5='+ str(answer))
    answer = 1+1
    print('1+1='+ str(answer))

    answer = 17 / 3
    print('17 / 3='+ str(answer))
    answer = 17 // 3
    print('17 // 3='+ str(answer))
    answer = 17 % 3
    print('17 % 3='+ str(answer))
    answer = 5 * 3 + 2
    print('5 * 3 + 2='+ str(answer))
    answer = 5 ** 2
    print(' 5 ** 2='+ str(answer))
    answer = 2 ** 7
    print(' 2 ** 7='+ str(answer))
