# Mastering Python Order of Operations

Have you ever written a complex mathematical expression in Python and gotten the wrong answer? It might be due to a misunderstanding of the order of operations in Python. In this article, we’ll go over the basics of Python order of operations and how to use parentheses to control the order of evaluation.

Contents

## What is the Order of Operations?

It is a defined set of rules that dictate the order in which mathematical operations are performed. In mathematics, we often represent the order of operations by the acronym PEMDAS.

The order of operations is similar in Python, but with a few differences:

1. Parentheses
2. Exponents
3. Multiplication, Division, and Modulo (from left to right)
4. Addition and Subtraction (from left to right)

Let’s take a look at some examples to see how this works in practice.

## Using Parentheses

The first step in evaluating an expression in Python is to evaluate any expressions inside parentheses. For example:

```>>> (2 + 3) * 4
20

```

In this expression, the addition of `2 + 3` is evaluated first, resulting in `5`. The expression inside the parentheses is then treated as a single value, so `5 * 4` is evaluated next, giving us the final result of `20`.

## Exponents

Exponents in Python are evaluated next. The operator for exponents is `**`. For example:

```>>> 2**3
8

```

In this expression, `2` is the base and `3` is the exponent, resulting in `8`.

## Multiplication, Division, and Modulo

Next, Python evaluates any expressions involving multiplication, division, or modulo. We perform multiplication and division from left to right. For example:

```>>> 4 * 3 / 2
6.0

```

In this expression, `4 * 3` is evaluated first, resulting in `12`. Then, `12 / 2` is evaluated, giving us the final result of `6.0`.

To get the remainder of a division operation, we use the modulo % operator. For example:

```>>> 7 % 3
1

```

In this expression, `7` divided by `3` has a remainder of `1`, so `1` is the result.

Finally, the language evaluates any remaining expressions involving addition and subtraction from left to right. For example:

```>>> 2 + 3 - 1
4

```

In this expression, `2 + 3` is evaluated first, resulting in `5`. Then, `5 - 1` is evaluated, giving us the final result of `4`.

## Tips for Writing Complex Expressions

When writing complex expressions in Python, it can be helpful to use parentheses to control the order of evaluation. For example:

```>>> 2 * (3 + 4)
14

```

In this expression, the expression inside the parentheses is evaluated first, resulting in `7`. Then, `2 * 7` is evaluated, giving us the final result of `14`.

```>>> 2 * (3 + 4) / 2 - 3
5.0
```

In this expression, the parentheses are evaluated first, resulting in `7`. Then, `2 * 7 / 2` is evaluated, giving us `7.0`. Finally, `7.0 - 3` is evaluated, giving us the final result of `5.0`.

We use parentheses and whitespace to make complex expressions easier to read and understand. This prevent mistakes and makes our code more maintainable.

## Python order of operations and/or

`and` operator has a higher precedence than the `or` operator.

This also means that when you have both `and` and `or` operators in an expression , the `and` operator evaluates first following the `or` operator. Here is an example:

```x = 2
y = 3
z = 4
x == 2 or y == 4 and z == 4

#Output
True
```

## Python order of operation boolean

In Python, boolean expressions are calculated using the order of operations defined by the language. This means that certain operations are performed before others based on their precedence in the hierarchy of operators.

The order of precedence for boolean operators in Python is as follows:

1. `not` has the highest precedence
2. `and` has higher precedence than `or`
3. `or` has the lowest precedence

This means that in a boolean expression with multiple operators, the `not` operator is evaluated first, then the `and` operator, and finally the `or` operator.

For example, consider the following boolean expression:

```not True or False and True
```

According to the order of precedence, the `not` operator is evaluated first, so the expression is equivalent to:

```False or False and True
```

Next, the `and` operator is evaluated, so the expression is equivalent to:

```False or False

```

Finally, the `or` operator is evaluated, so the entire expression evaluates to `False`.

## Python order of operations left to right

In Python, most operations are evaluated from left to right. This means that when you have an expression with multiple operators of the same precedence, the operators are evaluated in the order they appear in the expression, from left to right.

For example, consider the following expression:

```10 - 5 + 3
```

Since the `-` and `+` operators have the same precedence, we evaluate them from left to right. This means that the expression is equivalent to:

```(10 - 5) + 3
```

So the result is `8`.

However, there are some operators in Python that do not follow the left-to-right evaluation order. Like, the exponentiation operator `**` has a higher precedence than the arithmetic operators, which is evaluated from right to left. This means that an expression like `2 ** 3 ** 2` is evaluated as `2 ** (3 ** 2)`, which is `2 ** 9` or `512`.

## FAQs

How does the order of operations in Python compare to other programming languages?

The order of operations in Python is similar to most other programming languages, including C, Java, and JavaScript. The main difference is the order of precedence of operations, which can vary from language to language.

Can I use whitespace to make my code more readable?

Yes, you can use whitespace to make your code more readable by adding spaces between operators and operands, and using newlines to break up long expressions into multiple lines.

## Conclusion

Understanding the order of operations in Python is important for writing correct and efficient code. You can write complex mathematical expressions by using parentheses and order of operations to control the order of evaluation with confidence.

Remember, the order of operations in Python is:

1. Parentheses
2. Exponents
3. Multiplication, Division, and Modulo (from left to right)
4. Addition and Subtraction (from left to right)

By following these rules and using parentheses and whitespace, you can write complex expressions that are easy to read and understand.

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