# Operators

Python has the following major operators:

`<, >, =, ==, >=, <=, !=, *, +, -, **, +=, -=, /=, *=, in, and, not, is.`

## Operator priority

When expressions containing more than one operators are evaluated, the operator priority is followed, it is just like the BODMAS (PEMDAS for Americans) rule of maths. Usage of `()`

can override priority.

## Assignment

`=`

is the assignment operator.

## Multiply

## Exercise:

Take two numbers from the user and print their multiplication.

Take three numbers from the user and print their multiplication.

## Add

## Exercise:

Take two strings from a variable and print their concatenation.

Take two numbers from the user and add them (you need to use the int() to convert the input to integer)

Take three numbers from the user and print their addition.

## Equality

`==`

is the equality operator, it returns true if both operands have the same value.

Note: It is a classic mistake to use

`==`

when you really want to use`=`

or vice versa.

## Division

`27/7`

divides 27 by 7 and returns a floating point result

`27//7`

divides 27 by 7 and returns an integer result.

## Power

`**`

is the operator for calculating power.

## Shortcut operators

Consider that you have to create a variable `a = 3`

. If you want to add `4`

to the variable `a`

.

You can do the following:

`a = a + 4`

. But this tends to be verbose.`a += 4`

: Another way to do exactly the same calculation.

`+=`

is a shortcut operator. There are other shortcut operators like: `+=, -=, /=, *=`

. No spaces are allowed between -=, +=.

In other languages, you can use `++`

or `--`

, but they are not available in Python.

## Membership test

The `in`

operator tests if the element on the left hand side is present in the right hand side sequence (list, tuple, set).

## Boolean operators

Read the docs

### not

Read the docs `not`

converts True to False and vice versa.

#### False like values

Variables of any data type when they are null or have no value, they are False like values. The negation of a False like value is True

#### True like

Variables of any data type when have *some* value, any value, they are True like values. The negation of a True like value is False

### or

OR is true when either of the operand is true.

### and

AND is true when both the operands are true.

### Comparision Operators

Read the docs

There are eight comparison operations in Python. They all have the same priority (which is higher than that of the Boolean operations). Comparisons can be chained arbitrarily; for example, x < y <= z is equivalent to x < y and y <= z, except that y is evaluated only once (but in both cases y <= z is not evaluated at all if x < y is found to be false).

This table summarizes the comparison operations:

Operation | Meaning |

< | strictly less than |

<= | less than or equal |

> | strictly greater than |

>= | greater than or equal |

== | equal |

!= | not equal |

is | object identity |

is not | negated object identity |

**Links**

Last updated