Python Operators

Operators are symbols that compare values, combine conditions, and produce True/False results.

Operators are used for:

• branching (if, elif, else)
• filtering data
• validation and decision logic

Knowing operators improves our ability to write clear analytics.

What Is an Operator?

An operator is a symbol that performs an operation on one or more values.

Example:

score > 5

• is the operator

• score and 5 are operands
• the result is a Boolean: True or False

Comparison Operators (Most Important)

Comparison operators compare two values and return True or False.

Operator	Meaning	Example
==	equal to	x == 10
!=	not equal to	x != 10
>	greater than	x > 10
<	less than	x < 10
>=	greater than or equal	x >= 10
<=	less than or equal	x <= 10

Examples:

age >= 18
score < 5.0
country == "USA"

These are the most common operators used in data analysis.

Boolean Operators (Combining Conditions)

Boolean operators combine multiple conditions.

Operator	Meaning	Example
and	both must be true	age >= 18 and age < 65
or	either can be true	status == "A" or status == "B"
not	reverses a condition	not is_active

Examples:

score >= 4.0 and score <= 7.5
region == "Europe" or region == "Asia"
not has_missing_values

Membership Operators (in, not in)

Membership operators test whether a value exists in a collection.

Operator	Meaning
in	value exists in a list, string, or set
not in	value does not exist

Examples:

"csv" in ["csv", "json", "excel"]
country not in banned_countries

This is commonly used when validating inputs or filtering data.

Identity Operators (is, is not)

Identity operators test whether two variables refer to the same object, not just equal values.

Operator	Meaning
is	same object
is not	different objects

Examples:

value is None
result is not None

Use is primarily when checking for None.

Arithmetic Operators (Brief Review)

Arithmetic operators perform mathematical calculations.

Operator	Meaning
+	addition
-	subtraction
*	multiplication
/	division
//	integer division
%	remainder
**	exponent

Examples:

total = count \* price
average = sum(values) / len(values)
remainder = total % 2

Operator Results Feed Branching

Operators are most often used inside if statements.

Example:

if score >= 6.0:
   print("High score")

The condition inside if must evaluate to True or False.

Common Mistakes

Using only one equal sign instead of two equal signs for comparison.

• One = is used to initialize or set a variable value.
• Two == are used to test for equality.

WRONG: if x = 5:

RIGHT: if x == 5: (Use == to compare)

Comparing incompatible types

WRONG: "5" > 3 (comparing a string to an int)

RIGHT: int("5") > 3 (Convert types explicitly when needed)