วันที่ 3 — ตัวดำเนินการ (Operators)

print(True)
print(False)

# Arithmetic Operations in Python
# Integers

print('Addition: ', 1 + 2)        # 3
print('Subtraction: ', 2 - 1)     # 1
print('Multiplication: ', 2 * 3)  # 6
print('Division: ', 4 / 2)        # 2.0  Division in Python gives floating number
print('Division: ', 6 / 2)        # 3.0         
print('Division: ', 7 / 2)        # 3.5
print('Division without the remainder: ', 7 // 2)   # 3,  gives without the floating number or without the remaining
print('Division without the remainder: ',7 // 3)    # 2
print('Modulus: ', 3 % 2)         # 1, Gives the remainder
print('Exponentiation: ', 2 ** 3) # 8 it means 2 * 2 * 2

# Floating numbers
print('Floating Point Number, PI', 3.14)
print('Floating Point Number, gravity', 9.81)

# Complex numbers
print('Complex number: ', 1 + 1j)
print('Multiplying complex numbers: ',(1+1j) * (1-1j))

# Declaring the variable at the top first

a = 3 # a is a variable name and 3 is an integer data type
b = 2 # b is a variable name and 2 is an integer data type

# Arithmetic operations and assigning the result to a variable
total          = a + b
diff           = a - b
product        = a * b
division       = a / b
remainder      = a % b
floor_division = a // b
exponential    = a ** b

# I should have used sum instead of total but sum is a built-in function - try to avoid overriding built-in functions
print(total) # if you do not label your print with some string, you never know where the result is coming from
print('a + b = ', total)
print('a - b = ', diff)
print('a * b = ', product)
print('a / b = ', division)
print('a % b = ', remainder)
print('a // b = ', floor_division)
print('a ** b = ', exponential)

print('== Addition, Subtraction, Multiplication, Division, Modulus ==')

# Declaring values and organizing them together
num_one = 3
num_two = 4

# Arithmetic operations
total     = num_one + num_two
diff      = num_two - num_one
product   = num_one * num_two
div       = num_two / num_one
remainder = num_two % num_one

# Printing values with label
print('total: ', total)
print('difference: ', diff)
print('product: ', product)
print('division: ', div)
print('remainder: ', remainder)

# Calculating area of a circle
radius = 10                                 # radius of a circle
area_of_circle = 3.14 * radius ** 2         # two * sign means exponent or power
print('Area of a circle:', area_of_circle)

# Calculating area of a rectangle
length = 10
width  = 20
area_of_rectangle = length * width
print('Area of rectangle:', area_of_rectangle)

# Calculating a weight of an object
mass    = 75
gravity = 9.81
weight  = mass * gravity
print(weight, 'N')                          # Adding unit to the weight

# Calculate the density of a liquid
mass    = 75    # in Kg
volume  = 0.075 # in cubic meter
density = mass / volume  # 1000 Kg/m^3
print(density, 'Kg/m^3') # Adding unit to the density

print(3 > 2)     # True, because 3 is greater than 2
print(3 >= 2)    # True, because 3 is greater than 2
print(3 < 2)     # False,  because 3 is greater than 2
print(2 < 3)     # True, because 2 is less than 3
print(2 <= 3)    # True, because 2 is less than 3
print(3 == 2)    # False, because 3 is not equal to 2
print(3 != 2)    # True, because 3 is not equal to 2
print(len('mango') == len('avocado'))  # False
print(len('mango') != len('avocado'))  # True
print(len('mango') < len('avocado'))   # True
print(len('milk') != len('meat'))      # False
print(len('milk') == len('meat'))      # True
print(len('tomato') == len('potato'))  # True
print(len('python') > len('dragon'))   # False


# Comparing something gives either a True or False

print('True == True: ', True == True)
print('True == False: ', True == False)
print('False == False:', False == False)

print('1 is 1', 1 is 1)                   # True - because the data values are the same
print('1 is not 2', 1 is not 2)           # True - because 1 is not 2
print('A in Asabeneh', 'A' in 'Asabeneh') # True - A found in the string
print('B not in Asabeneh', 'B' in 'Asabeneh') # False - there is no uppercase B
print('coding' in 'coding for all') # True - because coding for all has the word coding
print('a in an:', 'a' in 'an')      # True
print('4 is 2 ** 2:', 4 is 2 ** 2)  # True

print(3 > 2 and 4 > 3) # True - because both statements are true
print(3 > 2 and 4 < 3) # False - because the second statement is false
print(3 < 2 and 4 < 3) # False - because both statements are false
print('True and True: ', True and True)
print(3 > 2 or 4 > 3)  # True - because both statements are true
print(3 > 2 or 4 < 3)  # True - because one of the statements is true
print(3 < 2 or 4 < 3)  # False - because both statements are false
print('True or False:', True or False)
print(not 3 > 2)     # False - because 3 > 2 is true, then not True gives False
print(not True)      # False - Negation, the not operator turns true to false
print(not False)     # True
print(not not True)  # True
print(not not False) # False