Python Built-in Functions (without Import)
🧠Python has a variety of built-in functions (so-called built-in functions) and standard methods that you can use directly without importing anything. They are the toolkit for every Python beginner – and perfect for your students!
🧰 Python Built-in Functions (without Import) #
Here are the most important built-in functions with brief explanations:
| 🔧 Function | 🧩 Description | 🧪 Example |
|---|---|---|
print() |
Outputs text to the screen | print("Hello World") |
input() |
Gets input from the user | name = input("What's your name? ") |
len() |
Returns the length of an object | len("Python") |
type() |
Shows the data type of a value | type(42) |
int() |
Converts to an integer | int("5") |
float() |
Converts to a float | float("3.14") |
str() |
Converts to a string | str(100) |
bool() |
Converts to a boolean value | bool("") → False |
list() |
Creates a list | list("abc") → ['a', 'b', 'c'] |
dict() |
Creates a dictionary | dict(name="Lena", age=12) |
set() |
Creates a set (without duplicates) | set([1, 2, 2, 3]) → {1, 2, 3} |
tuple() |
Creates a tuple | tuple([1, 2]) → (1, 2) |
range() |
Generates a number sequence | range(5) → 0,1,2,3,4 |
sum() |
Adds all numbers in a list | sum([1, 2, 3]) → 6 |
max() |
Largest value | max([3, 7, 2]) → 7 |
min() |
Smallest value | min([3, 7, 2]) → 2 |
abs() |
Absolute value | abs(-5) → 5 |
round() |
Rounds a number | round(3.14159, 2) → 3.14 |
sorted() |
Sorts a list | sorted([3, 1, 2]) → [1, 2, 3] |
reversed() |
Reverses a sequence | list(reversed([1, 2, 3])) → [3, 2, 1] |
enumerate() |
Returns index + value | for i, v in enumerate(["a", "b"]) |
zip() |
Combines multiple lists | zip([1,2], ["a","b"]) |
help() |
Shows help for an object | help(str) |
id() |
Memory address of an object | id(x) |
eval() |
Executes a string as Python code | eval("2 + 2") → 4 |
isinstance() |
Checks type of an object | isinstance(5, int) → True |
📦 Common Methods for Standard Data Types #
🔤 String Methods #
text = "Python"
text.upper() # "PYTHON"
text.lower() # "python"
text.startswith("Py") # True
text.replace("Py", "My") # "Mython"
text.split("t") # ['Py', 'hon']
📋 List Methods #
numbers = [1, 2, 3]
numbers.append(4) # [1, 2, 3, 4]
numbers.pop() # removes last element
numbers.sort() # sorts the list
numbers.reverse() # reverses the order
📘 Dictionary Methods #
info = {"name": "Lena", "age": 12}
info.keys() # dict_keys(['name', 'age'])
info.values() # dict_values(['Lena', 12])
info.get("name") # "Lena"
info.update({"class": 6})
🔢 Set Methods #
s = {1, 2, 3}
s.add(4)
s.remove(2)
s.union({5, 6}) # {1, 3, 4, 5, 6}
🧠Tip for Students: #
Functions = Tools that you call
Methods = Tools that you use on an object