Ch 4 · Data Types — Kinds of Values · Python
Topic 4 of 13 in Python — Complete Tutorial (Beginner) — 5 lessons.
What is a Data Type?
Every piece of information stored in a program belongs to a category. A number like 42 is very different from a word like "Alice", even though the computer stores both in memory. Python uses the concept of a data type to keep these categories separate. A data type tells you what kind of value a variable holds — and what you can do with it. You can multiply two numbers, but multiplying two sentences makes no sense.
Numbers: int and float
Python has two main number types. An int is a whole number with no decimal point — your age, a count of students, a score. A float is a number with a decimal point — a price, an average, a measurement. Python automatically picks the right one, and it happily mixes them in calculations. One thing to know: ordinary division with / always produces a float, even when the result is whole. If you want a whole-number result, Python gives you a special "floor division" operator //.
Strings (str)
A string is any sequence of characters — letters, digits, spaces, punctuation, even emojis — wrapped inside quotation marks. Strings hold all the human-readable text in your program: names, sentences, messages, labels. In Python you can use single quotes '...' or double quotes "..." interchangeably. Strings come with many built-in tools called methods that let you transform and inspect text, and you call them with a dot after the string.
Booleans (bool)
A boolean is the simplest data type — it has exactly two possible values: True and False. Note the capital letters: Python is strict about this. Booleans are the language of decisions. Every time your program needs to choose between two paths, it relies on a boolean. When you write an if statement, the condition must evaluate to either True or False.
None and type()
Python has a special value called None that represents "nothing" or "no value yet." It is not zero and it is not an empty string — it is a deliberate way of saying "this is intentionally empty." For example, a winner variable might start as None before a game finishes, then get a real name once someone wins. None is Python's equivalent of "null" in other languages.
All topics in Python Beginner
- Introduction to Programming & Python
- Your First Python Program
- Variables — Your Data Containers
- Data Types — Kinds of Values
- Operators & Expressions
- Conditional Statements
- Loops & Iterations
- Functions
- Lists — Collections of Data
- Dictionaries & Classes
- Strings — Working with Text
- Error Handling
- Mini-Projects & Practice