Data Types and Structures

In programming, data type is an important concept. Variables can store data of different types, and different types can do different things.

Built-in Data Types

Python has the following data types built-in by default, in these categories:

• Text Type: str
• Numeric Types: int, float, complex
• Sequence Types: list, tuple, range
• Mapping Type: dict
• Set Types: set, frozenset
• Boolean Type: bool

Sequences: Lists and Tuples

Lists

Lists are used to store multiple items in a single variable. They are ordered and changeable.

fruits = ["apple", "banana", "cherry"]
fruits[1] = "blackcurrant"
print(fruits)

Tuples

Tuples are used to store multiple items in a single variable. They are ordered and unchangeable.

coordinates = (10, 20)
print(coordinates[0])

Mapping: Dictionaries

Dictionaries are used to store data values in key:value pairs. A dictionary is a collection which is ordered, changeable and does not allow duplicates.

car = {
  "brand": "Ford",
  "model": "Mustang",
  "year": 1964
}
print(car["brand"])

---

title: Control Flow description: Learn about if-else statements, for loops, and while loops in Python.

Python supports the usual logical conditions from mathematics.

Conditional Statements

If-Else

a = 33
b = 200
if b > a:
  print("b is greater than a")
elif a == b:
  print("a and b are equal")
else:
  print("a is greater than b")

Loops

For Loops

A for loop is used for iterating over a sequence (that is either a list, a tuple, a dictionary, a set, or a string).

fruits = ["apple", "banana", "cherry"]
for x in fruits:
  print(x)

While Loops

With the while loop we can execute a set of statements as long as a condition is true.

i = 1
while i < 6:
  print(i)
  i += 1