Data Types and Variables

Python has several built-in data types that can store different kinds of values. Some of the most common data types are:

• str: a string is a sequence of characters enclosed in quotes.

  • For example, name = "Alice" assigns a string value to the variable name.

• int: an integer is a whole number without a decimal point.

  • For example, age = 21 assigns an integer value to the variable age.

• float: a float is a number with a decimal point.

  • For example, pi = 3.14 assigns a float value to the variable pi.

• bool: a boolean is a logical value that can be either True or False.

  • For example, flag = True assigns a boolean value to the variable flag.

• list: a list is an ordered collection of values that can be of different types.

  • For example, colors = ["red", "green", "blue"] assigns a list value to the variable colors.

• tuple: a tuple is an immutable ordered collection of values that can be of different types.

  • For example, point = (1, 2) assigns a tuple value to the variable point.

• dict: a dictionary is an unordered collection of key-value pairs that can be of different types.

  • For example, person = {"name": "Bob", "age": 25} assigns a dictionary value to the variable person.

• set: a set is an unordered collection of unique values that can be of different types.

  • For example, letters = {"a", "b", "c"} assigns a set value to the variable letters.

• Python does not require explicit declaration of variables. A variable is created when a value is assigned to it using the = operator. For example, x = 5 creates a variable named x and assigns it the value 5.

• Python variables are dynamically typed, which means that their data type is determined at runtime based on the type of the value assigned to them. For example, if you assign a string value to a variable that previously had an integer value, the data type of the variable will change from int to str. For example, x = 5 makes x an int, but x = "hello" makes x a str.

• You can check the data type of any variable or value by using the built-in function type(). For example, type(x) will return the data type of x.

• You can also convert one data type to another by using the built-in functions that correspond to each data type. For example, int(x) will convert x to an int, and str(x) will convert x to a str.