Int

x = 1  
y = 2
z = x + y
print(z)

Making it interactive with input()

x = input ("whats x? ")
y = input ("whats y? ")
z = x + y
print (z)

Any input from keyboard is treated as a string. For input 2 and 2, output will be 22 as + is concatenating both numbers because they are treated as strings.

int isn't just a data type but also a function which can convert 2 from str type to int type. int() can be used to correct by converting them to integers.

x = int(input ("whats x? "))
y = int(input ("whats y? "))
print(x+y)

Argument moves from inner function, becomes input to outer function

print ( int( input("whats x? ")) + int(input("whats y? ")))

One line but very complicated and clever for its own good.

Float

4.1 is a float float - is any number with a decimal point

• when two numbers are divided, even if the result is a whole number, program always gives a float (2.0).
• any operation b/w float and int will be a float.
• large numbers can be made more readable by using _ , (1_00_00_000) python will only print the digits.

Round number to a nearest digit

round(number[, ndigits])     # [] code in square brackets means optional

round means just one number, but if more is needed then it can be specified.

Rounding to a nearest number

x = float (input ("whats x? "))
y = float (input("whats y? "))
z = round ( x + y )
print (z)

print ( f" {z:,} " )
# creating a f-string argument and then applying {z:,} makes the number have comma

# there isnt an upper bound on how large an int can be but float can get cut off into finite digits
z = round(x / y, 2)
# 2 in the argument of z allows rounding to nearest 2 decimals

z = x/y
print ( f"{z:.2f}" )
# by converting it into an f-strinf, format string i can round the result decimal to 2