Python: Playing With Numbers

Python allows you to represent and work with integers, decimal, and complex numbers efficiently.

Let us see some numbers:

• 0 is a number invented by Aryabhatta.

• 3.14 is called a pi number, it is a decimal number.

• 10 is a whole number.

• -1 is a negative number.

Now, how can we represent such numbers in Python?

Here, we have something new:

int
float
complex

The above classes are called numeric data types in Python.

Quick Links

Numbers in Python

Can we play with these numbers in Python

Floats and Constants in Python

#1: Numbers in Python

int is a class name for integers (1, 10, 25),

float is a class name for decimal numbers (3.14, 0.05, 1.05), and complex denotes complex numbers.

We can use our previous knowledge of variables and assignment operator = to initiate a number in Python.

number = 0

Voila! You have successfully represented a number in Python. You can try here.

Let's break it down:

We're assigning 0 to number, where number is a variable name. Here, = is the assignment operator used to allot 0 to number. Now, 0 lives in number.

You don’t need to explicitly specify the data type (int or float). You can write:

pi = 3.14

You can find out the data type of a number using the type() function.

type(pi)

Let's print it:

print(type(pi))

# You'll get this:
<class 'float'>

Be careful about the parentheses:

• The inner one is for the variable pi.

• The outer one is for the print function.

#2: Can we play with these numbers in Python—add, subtract, multiply?

Yes, of course! These operations are allowed:

# Operators
+ - / % **

Add operator (+):

10 + 10

Subtract operator (-):

10 - 10

Multiply operator (*):

10 * 10

Division operator (/):

10 / 10

Modulus operator (%):

It gives the remainder of a division.

For example:

10 % 3 # Remainder is 1

Exponent operator (**):

2 ** 2

Floor division operator (//):

10 // 3 # It leaves the decimal part of the answer

You can run all of these codes here.

Tip:

You can use spaces between the operator and numbers for better readability.

Order of Operations

Remember, Python follows standard operator precedence (PEMDAS/BODMAS rules).

#3: Floats and Constants in Python

Floats are basically decimal point numbers in Python. For example, 20 / 3 returns a floating point number.

division = 20 / 3
print(division)

# Returns
6.666666666666667

To format floating-point numbers, we use f-strings or the format method. Inside the parentheses, we first write f before ".

print(f"")

Now, we use a placeholder (curly braces {}) to write the variable name division in it.

print(f"{division}")

A modifier is then used to modify its value (6.666666666666667) in the desired format. Here, we want to print the result up to two decimal places, modifier :.2f 

print(f"{division:.2f}") # .2f represents upto two decimal places 

# More examples
{95:.2f} or 95.00

n = 1000000
print(f"{n:,}") # for using commas as a separator, it gives

1,000,000

x = 10.2
y = 10

x = int(x)
y = float(y)

Read more here. The use of int(x) or float(x) is called "casting." It is used to convert a number or string from one data type to another.

print(x)
print(y)

We can also use Python's round() function to round a number. Just pass the variable name inside the parentheses of the round() function.

number = 10.2345
round(number)

# It gives 10

You can round a number upto a given decimal places. Just pass the number of decimal places as an argument after a comma.

round(number, 2) # for rounding off upto 2 decimal places.

# It gives 10.23

Constants

Variables whose value doesn't change while your program runs are referred as constants.

A popular example is 3.14 or pi. There is no built-in function or data type in Python for constants. You can make your constants by writing their names in upper case and assigning the fixed value.

PI = 3.14

In the next post, we will learn about a new structure to store great things for you.

References

Sources