Python has several built-in types.
If you create the name
variable assigning it the value “Roger”, automatically this variable is now representing a String data type.
name = "Roger"
You can check which type a variable is using the type()
function, passing the variable as an argument, and then comparing the result to str
:
name = "Roger"
type(name) == str #True
Or using isinstance()
:
name = "Roger"
isinstance(name, str) #True
Notice that to see the
True
value in Python, outside of a REPL, you need to wrap this code insideprint()
, but for clarity reasons I avoid using it
We used the str
class here, but the same works for other data types.
First, we have numbers. Integer numbers are represented using the int
class. Floating point numbers (fractions) are of type float
:
age = 1
type(age) == int #True
fraction = 0.1
type(fraction) == float #True
You saw how to create a type from a value literal, like this:
name = "Flavio"
age = 20
Python automatically detects the type from the value type.
You can also create a variable of a specific type by using the class constructor, passing a value literal or a variable name:
name = str("Flavio")
anotherName = str(name)
You can also convert from one type to another by using the class constructor. Python will try to determine the correct value, for example extracting a number from a string:
age = int("20")
print(age) #20
fraction = 0.1
intFraction = int(fraction)
print(intFraction) #0
This is called casting. Of course this conversion might not always work depending on the value passed. If you write test
instead of 20
in the above string, you’ll get a ValueError: invalid literal for int() with base 10: 'test'
error.
Those are just the basics of types. We have a lot more types in Python:
complex
for complex numbersbool
for booleanslist
for liststuple
for tuplesrange
for rangesdict
for dictionariesset
for sets
and more!
We’ll explore them all soon.
More python tutorials:
- Introduction to Python
- Installing Python 3 on macOS
- Running Python programs
- Python 2 vs Python 3
- The basics of working with Python
- Python Data Types
- Python Operators
- Python Strings
- Python Booleans
- Python Numbers
- Python, Accepting Input
- Python Control Statements
- Python Lists
- Python Tuples
- Python Sets
- Python Dictionaries
- Python Functions
- Python Objects
- Python Loops
- Python Modules
- Python Classes
- The Python Standard Library
- Debugging Python
- Python variables scope
- Python, accept arguments from command line
- Python Recursion
- Python Nested Functions
- Python Lambda Functions
- Python Closures
- Python Virtual Environments
- Use a GoPro as a remote webcam using Python
- Python, how to create a list from a string
- Python Decorators
- Python Docstrings
- Python Introspection
- Python Annotations
- Python, how to list files and folders in a directory
- Python, how to check if a number is odd or even
- Python, how to get the details of a file
- Python, how to check if a file or directory exists
- Python Exceptions