- A variable can have any number of values, but just one at a time.
- Python variable names haven’t any inherent aiming to Python.
- Variables are containers for storing data values.
How to create a variable?
- Python has no command for declaring a variable.
- A variable is made the instant you initially assign a worth thereto.
- The variables don’t get to be asked with any particular type, and may even change type after they need been set.
- We will assign variety to a variable.
- A variable name cannot be varied. But you’ll include numbers during a variable name—-as long as you do not begin the name with variety.
- String variables are often declared either by using single or quotation marks.
Names of variable
- A variable can have a brief name(like x and y) or a more descriptive name (department, School name,total_cost).
for Python variable
- Always remember that the variable name must start with a letter or the underscore character.
- The variable name cannot start with variety.
- Note that a variable name can only contain alpha-numeric characters and underscores (A-Z, 0-9, and _)
- Also note that the variable names are case-sensitive (age, Age, and AGE are three different variables)
- We will use the +character to feature a variable to a different variable.
- Variables that are created outside of a function (as altogether of the examples above) are referred to as global variables.
- Global variables are often employed by everyone, both inside functions and out of doors.
Common pitfalls with Variables Initialization
- We’ll want to watch out for a common mistake: forgetting to initialize variables. If we try to use a variable without first initializing it, we’ll run into a NameError.
- This is the Python interpreter catching the mistake and telling us that we’re using an undefined variable.
- The fix is pretty simple: initialize the variable by assigning the variable a value before we use it.
- Another common mistake to watch out for that can be a little trickier to spot is forgetting to initialize variables with the correct value.
- If we use a variable earlier in our code and then reuse it later in a loop without setting the value to something we want, our code may wind up doing something we didn’t expect.
- Don’t forget to initialize our variables before using them.