A boolean data type represents one of the two values: True or False. The use of these data types will be clear once we start using the comparison operator. The first letter T for True and F for False should be capital unlike JavaScript. Example: Boolean Values
print(True) print(False)Python language supports several types of operators. In this section, we will focus on few of them.
Assignment operators are used to assign values to variables. Let us take = as an example. Equal sign in mathematics shows that two values are equal, however in Python it means we are storing a value in a certain variable and we call it assignment or a assigning value to a variable. The table below shows the different types of python assignment operators, taken from w3school.
- Addition(+): a + b
- Subtraction(-): a - b
- Multiplication(*): a * b
- Division(/): a / b
- Modulus(%): a % b
- Floor division(//): a // b
- Exponentiation(**): a ** b
Example:Integers
# Arithmetic Operations in Python# Integersprint('Addition: ', 1+2) # 3print('Subtraction: ', 2-1) # 1print('Multiplication: ', 2*3) # 6print ('Division: ', 4/2) # 2.0 Division in Python gives floating numberprint('Division: ', 6/2) # 3.0 print('Division: ', 7/2) # 3.5print('Division without the remainder: ', 7//2) # 3, gives without the floating number or without the remainingprint ('Division without the remainder: ',7//3) # 2print('Modulus: ', 3%2) # 1, Gives the remainderprint('Exponentiation: ', 2**3) # 9 it means 2 * 2 * 2Example:Floats
# Floating numbersprint('Floating Point Number, PI', 3.14) print('Floating Point Number, gravity', 9.81)Example:Complex numbers
# Complex numbersprint('Complex number: ', 1+1j) print('Multiplying complex numbers: ',(1+1j) * (1-1j))Let's declare a variable and assign a number data type. I am going to use single character variable but remember do not develop a habit of declaring such types of variables. Variable names should be all the time mnemonic.
Example:
# Declaring the variable at the top firsta=3# a is a variable name and 3 is an integer data typeb=2# b is a variable name and 3 is an integer data type# Arithmetic operations and assigning the result to a variabletotal=a+bdiff=a-bproduct=a*bdivision=a/bremainder=a%bfloor_division=a//bexponential=a**b# I should have used sum instead of total but sum is a built-in function - try to avoid overriding built-in functionsprint(total) # if you do not label your print with some string, you never know where the result is coming fromprint('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 = ', exponentiation)Example:
print('== Addition, Subtraction, Multiplication, Division, Modulus ==') # Declaring values and organizing them togethernum_one=3num_two=4# Arithmetic operationstotal=num_one+num_twodiff=num_two-num_oneproduct=num_one*num_twodiv=num_two/num_oneremainder=num_two%num_one# Printing values with labelprint('total: ', total) print('difference: ', diff) print('product: ', product) print('division: ', div) print('remainder: ', remainder)Let us start start connecting the dots and start making use of what we already know to calculate (area, volume,density, weight, perimeter, distance, force).
Example:
# Calculating area of a circleradius=10# radius of a circlearea_of_circle=3.14*radius**2# two * sign means exponent or powerprint('Area of a circle:', area_of_circle) # Calculating area of a rectanglelength=10width=20area_of_rectangle=length*widthprint('Area of rectangle:', area_of_rectangle) # Calculating a weight of an objectmass=75gravity=9.81weight=mass*gravityprint(weight, 'N') # Adding unit to the weight# Calculate the density of a liquidmass=75# in Kgvolume=0.075# in cubic meterdensity=mass/volume# 1000 Kg/m^3In programming we compare values, we use comparison operators to compare two values. We check if a value is greater or less or equal to other value. The following table shows Python comparison operators which was taken from w3shool.
Example: Comparison Operators
print(3>2) # True, because 3 is greater than 2print(3>=2) # True, because 3 is greater than 2print(3<2) # False, because 3 is greater than 2print(2<3) # True, because 2 is less than 3print(2<=3) # True, because 2 is less than 3print(3==2) # False, because 3 is not equal to 2print(3!=2) # True, because 3 is not equal to 2print(len('mango') ==len('avocado')) # Falseprint(len('mango') !=len('avocado')) # Trueprint(len('mango') <len('avocado')) # Trueprint(len('milk') !=len('meat')) # Falseprint(len('milk') ==len('meat')) # Trueprint(len('tomato') ==len('potato')) # Trueprint(len('python') >len('dragon')) # False# Comparing something gives either a True or Falseprint('True == True: ', True==True) print('True == False: ', True==False) print('False == False:', False==False)In addition to the above comparison operator Python uses:
- is: Returns true if both variables are the same object(x is y)
- is not: Returns true if both variables are not the same object(x is not y)
- in: Returns True if the queried list contains a certain item(x in y)
- not in: Returns True if the queried list doesn't have a certain item(x in y)
print('1 is 1', 1is1) # True - because the data values are the sameprint('1 is not 2', 1isnot2) # True - because 1 is not 2print('A in Asabeneh', 'A'in'Asabeneh') # True - A found in the stringprint('B in Asabeneh', 'B'in'Asabeneh') # False - there is no uppercase Bprint('coding'in'coding for all') # True - because coding for all has the word codingprint('a in an:', 'a'in'an') # Trueprint('4 is 2 ** 2:', 4is2**2) # TrueUnlike other programming languages python uses keywords and, or and not for logical operators. Logical operators are used to combine conditional statements:
print(3>2and4>3) # True - because both statements are trueprint(3>2and4<3) # False - because the second statement is falseprint(3<2and4<3) # False - because both statements are falseprint('True and True: ', TrueandTrue) print(3>2or4>3) # True - because both statements are trueprint(3>2or4<3) # True - because one of the statements is trueprint(3<2or4<3) # False - because both statements are falseprint('True or False:', TrueorFalse) print(not3>2) # False - because 3 > 2 is true, then not True gives Falseprint(notTrue) # False - Negation, the not operator turns true to falseprint(notFalse) # Trueprint(notnotTrue) # Trueprint(notnotFalse) # False🌕 You have boundless energy. You have just completed day 3 challenges and you are three steps ahead on your way to greatness. Now do some exercises for your brain and your muscles.
- Declare your age as integer variable
- Declare your height as a float variable
- Declare a variable that store a complex number
- Write a script that prompts the user to enter base and height of the triangle and calculate an area of this triangle (area = 0.5 x b x h).
Enterbase: 20Enterheight: 10Theareaofthetriangleis100- Write a script that prompts the user to enter side a, side b, and side c of the triangle. Calculate the perimeter of the triangle (perimeter = a + b + c).
Entersidea: 5Entersideb: 4Entersidec: 3Theperimeterofthetriangleis12- Get length and width of a rectangle using prompt. Calculate its area (area = length x width) and perimeter (perimeter = 2 x (length + width))
- Get radius of a circle using prompt. Calculate the area (area = pi x r x r) and circumference (c = 2 x pi x r) where pi = 3.14.
- Calculate the slope, x-intercept and y-intercept of y = 2x -2
- Slope is (m = y2-y1/x2-x1). Find the slope and Euclidean distance between point (2, 2) and point (6,10)
- Compare the slopes in tasks 8 and 9.
- Calculate the value of y (y = x^2 + 6x + 9). Try to use different x values and figure out at what x value y is going to be 0.
- Find the length of 'python' and 'dragon' and make a falsy comparison statement.
- Use and operator to check if 'on' is found in both 'python' and 'dragon'
- I hope this course is not full of jargon. Use in operator to check if jargon is in the sentence.
- There is no 'on' in both dragon and python
- Find the length of the text python and convert the value to float and convert it to string
- Even numbers are divisible by 2 and the remainder is zero. How do you check if a number is even or not using python?
- Check if the floor division of 7 by 3 is equal to the int converted value of 2.7.
- Check if type of '10' is equal to type of 10
- Check if int('9.8') is equal to 10
- Writ a script that prompts the user to enter hours and rate per hour. Calculate pay of the person?
Enterhours: 40Enterrateperhour: 28Yourweeklyearningis1120- Write a script that prompts the user to enter number of years. Calculate the number of seconds a person can live. Assume a person can live hundred years
Enternumberofyearsyouhavelived: 100Youhavelivedfor3153600000seconds.- Write a Python script that displays the following table
1111121248313927414166451525125🎉 CONGRATULATIONS ! 🎉
