Variables
- Variables are containers for storing data values.
- Unlike other programming languages, Python has no command for declaring a variable.
- A variable is created the moment you first assign a value to it
Example :
x = 5
y = "John"
print(x)
print(y)Variables do not need to be declared with any particular type and can even change type after they have been set.
x = 4
x = "Sally"
print(x)
String variables can be declared either by using single or double quotes:
x = "John" // is the same as
x = 'John'
Variable Names A variable can have a short name (like x and y) or a more descriptive name (age, carname, total_volume). Rules for Python variables:
- A variable name must start with a letter or the underscore character
- A variable name cannot start with a number
- A variable name can only contain alpha-numeric characters and underscores (A-z,0-9,and _)
- Variable names are case-sensitive (age, Age and AGE are three different variables)
Assign Value to Multiple Variables Python allows you to assign values to multiple variables in one line:
Example
x, y, z = "Orange", "Banana", "Cherry"
print(x)
print(y)
print(z)
```
And you can assign the same value to multiple variables in one line:
```
Example
x = y = z = "Orange"
print(x)
print(y)
print(z)
```
The Python print statement is often used to output variables.
To combine both text and a variable, Python uses the + character:
Example
```
x = "awesome"
print("Python is " + x)
```
You can also use the + character to add a variable to another variable:
```
x = "Python is "
y = "awesome"
z = x + y
print(z)
```
For numbers, the + character works as a mathematical operator:
```
x = 5
y = 10
print(x + y)
```
If you try to combine a string and a number, Python will give you an error:
```
x = 5
y = "John"
print(x + y)
```