We'll start by talking about variables. In programming, a variable is a named location used to store data in memory.
It is called a variable because its value can vary throughout the execution of a program. Variables must be given
unique names, called identifiers. In Python, variable names are case sensitive and cannot start with a number. They
can contain letters, numbers, and underscores.
For example, let's say we want to store the number of apples I have in a variable named apples. We can do this with
the following code:
apples = 5
Now, apples is a variable that stores the value 5. We can use this variable in calculations, such as adding more
apples:
apples = apples + 3 print(apples)
This will output 8, because we added 3 to the value stored in the apples variable.
Next, let's talk about data types. A data type is an attribute that tells what kind of data a particular variable can hold.
There are several basic data types in Python, including int, float, str, and bool.
int is short for integer, which is a whole number, positive or negative, without decimals. For example:
num_apples = 10 num_oranges = -5
float is short for floating point number, which is a number with decimals. For example:
price_per_apple = 0.5 price_per_orange = 0.35
str is short for string, which is a sequence of characters surrounded by quotes. Strings can be enclosed in either
single quotes or double quotes. For example:
name = "Alice" greeting = 'Hello, world!'
bool is short for boolean, which is a logical value that can be either True or False. For example:
is_hungry = True is_tired = False
It is called a variable because its value can vary throughout the execution of a program. Variables must be given
unique names, called identifiers. In Python, variable names are case sensitive and cannot start with a number. They
can contain letters, numbers, and underscores.
For example, let's say we want to store the number of apples I have in a variable named apples. We can do this with
the following code:
apples = 5
Now, apples is a variable that stores the value 5. We can use this variable in calculations, such as adding more
apples:
apples = apples + 3 print(apples)
This will output 8, because we added 3 to the value stored in the apples variable.
Next, let's talk about data types. A data type is an attribute that tells what kind of data a particular variable can hold.
There are several basic data types in Python, including int, float, str, and bool.
int is short for integer, which is a whole number, positive or negative, without decimals. For example:
num_apples = 10 num_oranges = -5
float is short for floating point number, which is a number with decimals. For example:
price_per_apple = 0.5 price_per_orange = 0.35
str is short for string, which is a sequence of characters surrounded by quotes. Strings can be enclosed in either
single quotes or double quotes. For example:
name = "Alice" greeting = 'Hello, world!'
bool is short for boolean, which is a logical value that can be either True or False. For example:
is_hungry = True is_tired = False
