DEV Community: Kiyanna Gayle

Python - Variable Names

Kiyanna Gayle — Sat, 03 Feb 2024 14:44:17 +0000

Variable Names

Legal variable names:
myvar = "John"
my_var = "John"
_my_var = "John"
myVar = "John"
MYVAR = "John"
myvar2 = "John"

Illegal variable names:
2myvar = "John"
my-var = "John"
my var = "John"

Camel Case - each word, except the first, starts with a capital letter:
myVariableName = "John"

Pascal Case - each word starts with a capital letter:
MyVariableName = "John"

Snake Case - each word is separated by an underscore character:
my_variable_name = "John"

Kiyanna Gayle — Sat, 03 Feb 2024 14:10:10 +0000

Variables - containers for storing data values.

Creating Variables

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

Casting

If you want to specify the data type of a variable, this can be done with casting.

x = str(3) # x will be '3'
y = int(3) # y will be 3
z = float(3) # z will be 3.0

Get the Type

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

x = 5
y = "John"
print(type(x))
print(type(y))

Kiyanna Gayle — Sat, 03 Feb 2024 13:48:04 +0000

Comments can be used to ...

Creating a Comment
-starts with "#"

Create a Comment in VSCode, the easy way. On Windows, the shortcut is: CTRL + / On Mac, the shortcut is: Command + /*

Example

#This is a comment
print("Hello, World!")

Python will ignore string literals that are not assigned to a variable.

add a multiline string (triple quotes) in your code and place your comment inside it.

"""
This is a comment
written in
more than just one line
"""

Kiyanna Gayle — Sat, 03 Feb 2024 13:31:51 +0000

Python is used for...

What can Python do?

Why Python?

works on different platforms (Windows, Mac, Linux, Raspberry Pi, etc.)
simple syntax that allows developers to write programs with fewer than other programming languages.
run on an interpreter system, meaning that code can be executed as soon as it is written. Prototyping can be rapid.
can be treated procedurally, in an object-oriented way, or a functional way.