Built-in Functions
Python comes with a rich set of built-in functions that you can use right out of the box without needing to install or import anything. These functions make programming faster and easier by providing ready-made solutions for common tasks.
1. Input and Output Functions
| Function | Description |
|---|---|
| print() | Prints output to the screen. |
| input() | Takes user input as a string. |
Example :
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name = input("Enter your name: ") # Takes input from user print("Hello, Python!") # Output: Hello, Python!
2. Type Conversion Functions
| Function | Description |
|---|---|
| int() | Converts a value to an integer. |
| float() | Converts a value to a floating-point number. |
| str() | Converts a value to a string. |
| bool() | Converts a value to a boolean. |
| complex() | Converts to a complex number. |
| list() | Converts to a list. |
| tuple() | Converts to a tuple. |
| set() | Converts to a set. |
| frozenset() | Converts to an immutable set. |
| dict() | Converts to a dictionary. |
| bytes() | Converts to a bytes object. |
| bytearray() | Converts to a mutable byte array. |
| memoryview() | Creates a memory view object. |
Example :
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int("10") # Output: 10 float("3.14") # Output: 3.14 str(123) # Output: '123' bool(0) # Output: False complex(1, 2) # Output: (1+2j) list("abc") # Output: ['a', 'b', 'c'] tuple([1, 2, 3]) # Output: (1, 2, 3) set([1, 2, 2]) # Output: {1, 2} frozenset([1, 2, 3]) # Output: frozenset({1, 2, 3}) dict(a=1, b=2) # Output: {'a': 1, 'b': 2} bytes(5) # Output: b'\x00\x00\x00\x00\x00' bytearray(3) # Output: bytearray(b'\x00\x00\x00') memoryview(b'abc')
3. String Functions
| Function | Description |
|---|---|
| ord() | Converts a character to its Unicode code. |
| chr() | Converts a Unicode code to its character. |
| ascii() | Returns a readable version of a string. |
| repr() | Returns a string representation of an object. |
Example :
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ord('A') # Output: 65 chr(65) # Output: 'A' ascii('ðŸ') # Output: "'\U0001f40d'" repr(3.14) # Output: '3.14'
4. Math Functions
| Function | Description |
|---|---|
| abs() | Returns the absolute value. |
| round() | Rounds a number to the nearest integer. |
| pow() | Returns x raised to the power y. |
| divmod() | Returns quotient and remainder as a tuple. |
| min() | Returns the smallest value. |
| max() | Returns the largest value. |
| sum() | Returns the sum of all items. |
Example :
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abs(-10) # Output: 10 round(3.14) # Output: 3 pow(2, 3) # Output: 8 divmod(10, 3) # Output: (3, 1) min(1, 2, 3) # Output: 1 max(1, 2, 3) # Output: 3 sum([1, 2, 3]) # Output: 6
5. Iterable and Sequence Functions
| Function | Description |
|---|---|
| len() | Returns the number of items. |
| sorted() | Returns a sorted list. |
| reversed() | Returns a reversed iterator. |
| enumerate() | Adds an index to an iterable. |
| all() | Returns True if all elements are true. |
| any() | Returns True if any element is true. |
| range() | Generates a sequence of numbers. |
| zip() | Combines iterables into pairs. |
| map() | Applies a function to each item. |
| filter() | Filters items based on a condition. |
Example:
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len("Python") # Output: 6 sorted([3, 1, 2]) # Output: [1, 2, 3] list(reversed([1, 2, 3])) # Output: [3, 2, 1] list(enumerate("abc")) # Output: [(0, 'a'), (1, 'b'), (2, 'c')] all([True, False]) # Output: False any([True, False]) # Output: True list(range(3)) # Output: [0, 1, 2] list(zip("abc", [1, 2, 3])) # Output: [('a', 1), ('b', 2), ('c', 3)] list(map(str.upper, "abc")) # Output: ['A', 'B', 'C'] list(filter(lambda x: x > 1, [0, 1, 2])) # Output: [2]
6. Object and Attribute Functions
| Function | Description |
|---|---|
| type() | Returns the type of an object. |
| id() | Returns the memory address of an object. |
| isinstance() | Checks if an object is of a type. |
| issubclass() | Checks if a class is a subclass. |
| getattr() | Gets the value of an object's attribute. |
| setattr() | Sets the value of an object's attribute. |
| delattr() | Deletes an attribute. |
| hasattr() | Checks if an object has an attribute. |
| callable() | Checks if an object is callable. |
| dir() | Returns all attributes and methods of an object. |
| vars() | Returns __dict__ attribute of an object. |
Example:
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type(123) # Output: <class 'int'> id(123) # Output: 140714374146296 isinstance(123, int) #Output: True issubclass(bool, int) #Output: True getattr(obj, "attr") setattr(obj, "attr", value) delattr(obj, "attr") hasattr(obj, "attr") #Output: True callable(len) #Output: True dir([]) vars(obj)
7. Memory and Data Representation Functions
| Function | Description |
|---|---|
| bin() | Converts to binary. |
| oct() | Converts to octal. |
| hex() | Converts to hexadecimal. |
| hash() | Returns the hash value of an object. |
Example
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bin(5) # Output: '0b101' oct(8) # Output: '0o10' hex(255) # Output: '0xff' hash("Python") # Output: -4053829851421555031
8. File and System Functions
| Function | Description |
|---|---|
| open() | Opens a file. |
| compile() | Compiles source code to bytecode. |
| exec() | Executes dynamically compiled Python code. |
| eval() | Evaluates a Python expression. |
Example
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file = open("example.txt", "r") code = compile("print('Hello')", "", "exec") exec("print('Hello')") eval("2 + 2") Output: 4
9. Debugging and Help Functions
| Function | Description |
|---|---|
| help() | Displays documentation for an object. |
| globals() | Returns a dictionary of global variables. |
| locals() | Returns a dictionary of local variables. |
| exit() | Exits Python. |
Example:
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help(print) globals() locals() exit()
10. Class and Object Functions
| Function | Description |
|---|---|
| staticmethod() | Creates a static method. |
| classmethod() | Creates a class method. |
| property() | Creates a property object. |
| super() | Refers to the parent class. |
Example:
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staticmethod(func) classmethod(func) property(fget, fset, fdel) super().__init__()
