Python Program to Convert Celsius To Fahrenheit

To understand this example, you should have the knowledge of the following Python programming topics:

• Python Data Types
• Python Basic Input and Output
• Python Operators

In the program below, we take a temperature in degree Celsius and convert it into degree Fahrenheit. They are related by the formula:

fahrenheit = celsius * 1.8 + 32

Source Code

# Python Program to convert temperature in celsius to fahrenheit

# change this value for a different result
celsius = 37.5

# calculate fahrenheit
fahrenheit = (celsius * 1.8) + 32
print('%0.1f degree Celsius is equal to %0.1f degree Fahrenheit' %(celsius,fahrenheit))

Output

37.5 degree Celsius is equal to 99.5 degree Fahrenheit

We encourage you to create a Python program to convert Fahrenheit to Celsius on your own using the following formula

celsius = (fahrenheit - 32) / 1.8

Python Program to Convert Kilometers to Miles

To understand this example, you should have the knowledge of the following Python programming topics:

• Python Data Types
• Python Basic Input and Output
• Python Operators

Example: Kilometers to Miles

# Taking kilometers input from the user
kilometers = float(input("Enter value in kilometers: "))

# conversion factor
conv_fac = 0.621371

# calculate miles
miles = kilometers * conv_fac
print('%0.2f kilometers is equal to %0.2f miles' %(kilometers,miles))

Output

Enter value in kilometers: 3.5
3.50 kilometers is equal to 2.17 miles

Here, the user is asked to enter kilometers. This value is stored in the kilometers variable.

Since 1 kilometer is equal to 0.621371 miles, we can get the equivalent miles by multiplying kilometers with this factor.

Your turn: Modify the above program to convert miles to kilometers using the following formula and run it.

kilometers = miles / conv_fac

Python Program to Generate a Random Number

To understand this example, you should have the knowledge of the following Python programming topics:

• Python Basic Input and Output
• Python Random Module

To generate random number in Python, randint() function is used. This function is defined in random module.

Source Code

# Program to generate a random number between 0 and 9

# importing the random module
import random

print(random.randint(0,9))

Output

5

Note that we may get different output because this program generates random number  in range 0 and 9. The syntax of this function is:

random.randint(a,b)

This returns a number N in the inclusive range [a,b], meaning a <= N <= b, where the endpoints are included in the range.

Python Program to Swap Two Variables

To understand this example, you should have the knowledge of the following Python programming topics:

• Python Data Types
• Python Basic Input and Output
• Python Operators

Source Code: Using a temporary variable

Code Visualization: Want to see exactly how variable swapping works? Step through each line with our new code visualizer. Try it yourself!

# Python program to swap two variables

x = 5
y = 10

# To take inputs from the user
#x = input('Enter value of x: ')
#y = input('Enter value of y: ')

# create a temporary variable and swap the values
temp = x
x = y
y = temp

print('The value of x after swapping: {}'.format(x))
print('The value of y after swapping: {}'.format(y))

Output

The value of x after swapping: 10
The value of y after swapping: 5

In this program, we use the temp variable to hold the value of x temporarily. We then put the value of y in x and later temp in y. In this way, the values get exchanged.

Source Code: Without Using Temporary Variable

In Python, there is a simple construct to swap variables. The following code does the same as above but without the use of any temporary variable.

x = 5
y = 10

x, y = y, x
print("x =", x)
print("y =", y)

If the variables are both numbers, we can use arithmetic operations to do the same. It might not look intuitive at first sight. But if you think about it, it is pretty easy to figure it out. Here are a few examples

Addition and Subtraction

x = x + y
y = x - y
x = x - y

Multiplication and Division

x = x * y
y = x / y
x = x / y

XOR swap

This algorithm works for integers only

x = x ^ y
y = x ^ y
x = x ^ y

Also Read:

• Python String swapcase()

Python Program to Solve Quadratic Equation

To understand this example, you should have the knowledge of the following Python programming topics:

• Python Data Types
• Python Basic Input and Output
• Python Operators

The standard form of a quadratic equation is:

ax2 + bx + c = 0, where
a, b and c are real numbers and
a ≠ 0

The solutions of this quadratic equation is given by:

(-b ± (b ** 2 - 4 * a * c) ** 0.5) / (2 * a)

Source Code

# Solve the quadratic equation ax**2 + bx + c = 0

# import complex math module
import cmath

a = 1
b = 5
c = 6

# calculate the discriminant
d = (b**2) - (4*a*c)

# find two solutions
sol1 = (-b-cmath.sqrt(d))/(2*a)
sol2 = (-b+cmath.sqrt(d))/(2*a)

print('The solution are {0} and {1}'.format(sol1,sol2))

Output

Enter a: 1
Enter b: 5
Enter c: 6
The solutions are (-3+0j) and (-2+0j)

We have imported the cmath module to perform complex square root. First, we calculate the discriminant and then find the two solutions of the quadratic equation.

You can change the value of a, b and c in the above program and test this program.

Also Read:

• Python Program to Find the Square Root

Before we wrap up, let’s put your understanding of this example to the test! Can you solve the following challenge?

Challenge:

Write a function to solve a quadratic equation.

• Define a function that takes three integers as input representing the coefficients of a quadratic equation.
• Return the roots of the quadratic equation.
• Hint: The quadratic formula is x = [-b ± sqrt(b^2 - 4ac)] / (2a).
• The term inside the square root, b^2 - 4ac, is called the discriminant.

1. If it’s positive, there are two real roots.
2. If it’s zero, there’s one real root.
3. If it’s negative, there are two complex roots.

• While returning the list, make sure the solution of [-b + sqrt(b^2 – 4ac)] / (2a) appears as the first solution.

1. import math

2. def solve_quadratic(a, b, c):

Python Program to Calculate the Area of a Triangle

To understand this example, you should have the knowledge of the following Python programming topics:

• Python Basic Input and Output
• Python Data Types
• Python Operators

If a, b and c are three sides of a triangle. Then,

s = (a+b+c)/2
area = √(s(s-a)*(s-b)*(s-c))

Source Code

# Python Program to find the area of triangle

a = 5
b = 6
c = 7

# Uncomment below to take inputs from the user
# a = float(input('Enter first side: '))
# b = float(input('Enter second side: '))
# c = float(input('Enter third side: '))

# calculate the semi-perimeter
s = (a + b + c) / 2

# calculate the area
area = (s*(s-a)*(s-b)*(s-c)) ** 0.5
print('The area of the triangle is %0.2f' %area)

Run Code

Output

The area of the triangle is 14.70

In this program, area of the triangle is calculated when three sides are given using Heron’s formula.

If you need to calculate area of a triangle depending upon the input from the user, input() function can be used.

Also Read:

• Python float()
• Python String Interpolation

Before we wrap up, let’s put your understanding of this example to the test! Can you solve the following challenge?

Challenge:

Write a function to find the area of a right angled triangle rounded off to two decimal places.

• For example, for inputs 3 and 4, the output should be 6.0.
• Reason: The area of a right-angled triangle is given by (1/2)*base*height. So, for base = 3 and height = 4, it’s (1/2)*3*4 = 6.0.

1 def triangle_area(base, height):

2