Lessons
Python Basics
Python Variables
Operators in Python
Conditional Statements in Python
Python Lists
Python Tuples
Python Sets
Python Dictionaries
Loops in Python
Python Arrays and Functions
Conclusion
Python Variable Names
Variable Names in Python
When naming your variables, you need to follow a few rules:
- A variable name must start with a letter or the underscore (
_
) character. - It cannot start with a number.
- Variable names can only contain letters, numbers, and underscores (A-z, 0-9, and
_
). - Variable names are case-sensitive (
age
,Age
, andAGE
are different variables).
Legal variable names:
python
1myvar = "Smith"
2_my_var = "Smith"
3myVar2 = "Smith"
Illegal variable names:
python
12myvar = "Smith" # Cannot start with a number
2my-var = "Smith" # Hyphens are not allowed
3my var = "Smith" # Spaces are not allowed
Python Case Sensitive
Variable names in Python are case-sensitive. This means that myVar
, MyVar
, and myvar
are all different variables.
Example:
python
1a = 4
2A = "Sally"
3# Here, a and A are two different variables
Python Multi-Word Variable Names
If your variable name has more than one word, there are a few common styles for writing it:
- Camel Case: Each word except the first starts with a capital letter.
python
1myVariableName = "Smith"
- Pascal Case: Every word starts with a capital letter.
python
1MyVariableName = "Smith"
- Snake Case: Each word is separated by an underscore.
python
1my_variable_name = "Smith"
Assigning Multiple Values to Variables
Python allows you to assign values to multiple variables at once.
Example:
python
1x, y, z = "Orange", "Grapes", "Cherry"
2print(x)
3print(y)
4print(z)
Assigning One Value to Multiple Variables
You can assign the same value to multiple variables in one line.
Example:
python
1x = y = z = "Orange"
2print(x)
3print(y)
4print(z)
Unpacking a Collection
If you have a collection (like a list or tuple), you can unpack its values into variables.
Example:
python
1fruits = ["Orange", "Grapes", "Cherry"]
2x, y, z = fruits
3print(x)
4print(y)
5print(z)