Python Program to Check if a Number is Positive or Negative

In this python tutorial, you will learn how to Check if a Number is Positive or Negative using the if, elif and else statements along with the greater and equality operators of the python programming language.

How to Check if a Number is Positive or Negative?

Let’s take a look at the source code , here the values are given as input by the user in the code, the == equality operator and the > greater than operator along with the if, elif and else statements carry out the function.

#program to Check if a Number is Positive or Negative

num = float(input("Enter a number: "))
if num > 0:
   print("\n{0} is a positive number".format(num))
elif num == 0:
   print("Zero")
else:
   print("\n{0} is a negative number".format(num))

INPUT:

-8659

OUTPUT:

Enter a number: 
-8659.0 is a negative number

1. Here we give the user the option to enter the values and the input values are scanned using the input function and are stored in the variable num with the statements/strings ("Enter a number: "),  we use the float function and declare the  input value as a decimal value.
2. In the STDIN section of the code editor the input values are entered.
3. We declare the if statement with the conditions as num > 0 followed by a colon : . If the conditions are met, the print  function will display the statement ("\n{0} is a positive number".format(num)) .
4. We declare the elif statement with the conditions as num == 0 followed by a colon : . If the conditions are met, the print  function will display the statement ("Zero") .
5. If neither of the above conditions are not met the else function will be executed and the print  function will display the statement ("\n{0} is a negative number".format(num)).
6. In the above lines of code, the variables {0} will hold the value of num where the format function helps in variable substitution and data formatting.

NOTE:

• The == equality is a comparison operator which returns True is the two items are equal and returns False if not equal.
• The > greater than operator is a comparison operator which returns True if the condition is satisfied, if not it returns false.
• The input() function allows a user to insert a value into a program, it returns a string value.
• The if and else statements evaluates whether an expression is true or false. If a condition is true, the “if” statement is executed otherwise, the “else” statement is executed.
• The elif is short for else if, it allows us to check for multiple expressions.
•  The colon : at the end of the if, elif and else statement tells Python that the next line of code should only be run if the condition is true.
• The statement for the input function are enclosed in single quotes and parenthesis.
• The \n in the code indicates a new line or the end of a statement line or a string.
• The print statement/string to be displayed in enclosed in double quotes.