Variables¶

Variables are containers used to store data values.

Creating a variable is very simple. You only need to name it and assign it a value. You don’t need to specify the data type of the variable when assigning it, because the variable is a reference, and it accesses objects of different data types through assignment.

Naming variables must follow the following rules:

Variable names can only contain numbers, letters, and underscores
The first character of the variable name must be a letter or underscore
Variable names are case sensitive

Create Variable¶

There is no command for declaring variables in MicroPython. Variables are created when you assign a value to it for the first time. It does not need to use any specific type declaration, and you can even change the type after setting the variable.

x = 8       # x is of type int
x = "lily" # x is now of type str
print(x)

>>> %Run -c $EDITOR_CONTENT
lily

Casting¶

If you want to specify the data type for the variable, you can do it by casting.

x = int(5)    # y will be 5
y = str(5)    # x will be '5'
z = float(5)  # z will be 5.0
print(x,y,z)

>>> %Run -c $EDITOR_CONTENT
5 5 5.0

Get the Type¶

You can get the data type of a variable with the type() function.

x = 5
y = "hello"
z = 5.0
print(type(x),type(y),type(z))

>>> %Run -c $EDITOR_CONTENT
<class 'int'> <class 'str'> <class 'float'>

Single or Double Quotes?¶

In MicroPython, single quotes or double quotes can be used to define string variables.

x = "hello"
# is the same as
x = 'hello'

Case-Sensitive¶

Variable names are case-sensitive.

a = 5
A = "lily"
#A will not overwrite a
print(a, A)

>>> %Run -c $EDITOR_CONTENT
5 lily