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Python Built in Functions
Python built-in functions are a core set of ready-to-use operations that form the foundation of Python programming. They are globally available without the need for imports and cover a wide range of functionalities, including data type conversions, object inspection, mathematical operations, algorithmic processing, and object-oriented programming support. Built-in functions are essential in backend development because they provide optimized, low-level implementations that prevent developers from reinventing common functionality, thereby improving performance, readability, and maintainability. When applied correctly, they reduce the likelihood of logical errors, minimize memory overhead, and promote algorithmic efficiency. These functions are deeply integrated with Python’s data structures (lists, dictionaries, sets, tuples, strings) and OOP principles, enabling developers to manipulate objects, enforce abstraction, and implement design patterns seamlessly. Readers of this reference will learn the exact syntax, purpose, and best practices for every built-in function in Python, supported by practical examples aligned with backend system architecture. They will also understand how to leverage built-ins for error prevention, memory management, and optimal algorithm design in real-world backend contexts.
Example
python
PYTHON Code
# Example demonstrating multiple built-in functions in a backend context
def process_user_data(values):
\# Ensure values is a list
if not isinstance(values, list):
raise TypeError("Input must be a list")
# Convert all items to integers safely
numeric_values = list(map(int, values))
# Filter out negative numbers using abs
positives = [abs(x) for x in numeric_values]
# Calculate statistics
total = sum(positives)
maximum = max(positives)
minimum = min(positives)
count = len(positives)
# Sort results for ordered processing
sorted_values = sorted(positives)
return {
"count": count,
"sum": total,
"max": maximum,
"min": minimum,
"sorted": sorted_values
}
# Example usage
data = \["-5", "10", "3", "-2"]
print(process_user_data(data))📊 Comprehensive Reference
| Function | Description | Syntax | Example | Notes |
|---|---|---|---|---|
| abs | Return absolute value | abs(x) | abs(-7) | Works with int, float, complex |
| all | Check if all elements are true | all(iterable) | all(\[1, True, 5]) | Empty iterable returns True |
| any | Check if any element is true | any(iterable) | any(\[0, False, 3]) | Empty iterable returns False |
| ascii | Return ASCII representation | ascii(object) | ascii("café") | Escapes non-ASCII chars |
| bin | Convert to binary string | bin(x) | bin(10) | Prefix "0b" |
| bool | Convert to Boolean | bool(x) | bool(\[]) | Empty -> False |
| breakpoint | Enter debugger | breakpoint() | breakpoint() | Uses pdb by default |
| bytearray | Mutable byte sequence | bytearray(\[source]) | bytearray(b"text") | Mutable vs bytes |
| bytes | Immutable byte sequence | bytes(\[source]) | bytes("abc","utf-8") | Immutable |
| callable | Check if callable | callable(obj) | callable(len) | Functions, classes return True |
| chr | Get character from Unicode | chr(i) | chr(65) | Reverse of ord() |
| classmethod | Define class method | @classmethod | classmethod(func) | Receives cls not self |
| compile | Compile source to code | compile(src,filename,mode) | compile("3+5","","eval") | Use with exec/eval |
| complex | Create complex number | complex(real, imag) | complex(2,3) | Supports strings |
| delattr | Delete attribute | delattr(obj,name) | delattr(obj,"attr") | Raises AttributeError if missing |
| dict | Create dictionary | dict(\[mapping]) | dict(a=1,b=2) | Flexible constructors |
| dir | List attributes | dir(\[obj]) | dir(str) | Includes methods, dunder methods |
| divmod | Return quotient & remainder | divmod(a,b) | divmod(9,2) | (quotient,remainder) |
| enumerate | Enumerate iterable | enumerate(iterable) | list(enumerate(\["a","b"])) | Supports start index |
| eval | Evaluate expression | eval(expr) | eval("3+5") | Be cautious: security risk |
| exec | Execute code | exec(obj) | exec("x=5") | Dynamic execution |
| filter | Filter items | filter(func,iterable) | list(filter(lambda x:x>0,\[1,-2,3])) | Returns iterator |
| float | Convert to float | float(x) | float("3.14") | Supports inf, nan |
| format | Format string | format(value,format_spec) | format(5,"03") | More in str.format |
| frozenset | Immutable set | frozenset(iterable) | frozenset(\[1,2,3]) | Hashable |
| getattr | Get attribute | getattr(obj,name\[,default]) | getattr(obj,"attr",0) | Avoids AttributeError |
| globals | Return global namespace | globals() | globals()\["name"] | Returns dict |
| hasattr | Check attribute | hasattr(obj,name) | hasattr(\[], "append") | Returns bool |
| hash | Return hash value | hash(obj) | hash("abc") | Object must be hashable |
| help | Interactive help | help(\[object]) | help(str) | Console utility |
| hex | Convert to hex string | hex(x) | hex(255) | Prefix "0x" |
| id | Return identity | id(obj) | id(42) | Unique per object lifetime |
| input | Read input | input(\[prompt]) | input("Name: ") | Returns str |
| int | Convert to integer | int(x\[,base]) | int("101",2) | Supports base conversion |
| isinstance | Check instance | isinstance(obj,cls) | isinstance(5,int) | Supports tuple of classes |
| issubclass | Check subclass | issubclass(cls,base) | issubclass(bool,int) | True if subclass |
| iter | Return iterator | iter(obj) | iter(\[1,2,3]) | Supports callable+sentinel |
| len | Length of object | len(obj) | len("abc") | Works with sequences, mappings |
| list | Create list | list(\[iterable]) | list("abc") | Mutable sequence |
| locals | Return local namespace | locals() | locals()\["x"] | Dynamic values |
| map | Apply function | map(func,iterable) | list(map(str,\[1,2])) | Returns iterator |
| max | Return max | max(iterable) | max(\[1,5,3]) | Supports key |
| memoryview | Create memory view | memoryview(obj) | memoryview(b"abc") | Efficient slicing |
| min | Return min | min(iterable) | min(\[1,5,3]) | Supports key |
| next | Get next item | next(iterator\[,default]) | next(iter(\[1,2])) | Raises StopIteration |
| object | Base object | object() | obj = object() | All classes inherit |
| oct | Convert to octal string | oct(x) | oct(8) | Prefix "0o" |
| open | Open file | open(file,mode) | open("f.txt","r") | Context manager |
| ord | Return Unicode code | ord(char) | ord("A") | Reverse of chr |
| pow | Power with mod | pow(x,y\[,z]) | pow(2,3,5) | Efficient with mod |
| Output text | print(obj) | print("Hello") | Multiple args | |
| property | Define property | @property | property(fget) | OOP encapsulation |
| range | Sequence of numbers | range(\[start],stop\[,step]) | range(5) | Lazy sequence |
| repr | Return repr string | repr(obj) | repr(\[1,2]) | Unambiguous form |
| reversed | Reverse iterator | reversed(seq) | list(reversed(\[1,2])) | Requires sequence |
| round | Round number | round(x\[,n]) | round(3.1415,2) | Bankers rounding |
| set | Create set | set(\[iterable]) | set("abc") | Mutable, unique |
| setattr | Set attribute | setattr(obj,name,value) | setattr(obj,"a",10) | Dynamic assignment |
| slice | Create slice | slice(start,stop\[,step]) | slice(1,5) | Used in slicing |
| sorted | Sorted list | sorted(iterable) | sorted(\[3,1,2]) | Supports key, reverse |
| staticmethod | Define static method | @staticmethod | staticmethod(func) | No self/cls |
| str | Create string | str(obj) | str(123) | Immutable |
| sum | Sum of items | sum(iterable\[,start]) | sum(\[1,2,3]) | Supports start value |
| super | Access parent class | super() | super().method() | OOP inheritance |
| tuple | Create tuple | tuple(\[iterable]) | tuple("ab") | Immutable sequence |
| type | Return type or create class | type(obj) | type(5) | Also dynamic class creation |
| vars | Return dict | vars(\[obj]) | vars(str) | Modifiable dict |
| zip | Aggregate iterables | zip(*iterables) | list(zip(\[1,2],\[3,4])) | Returns iterator |
| import | Import module | import(name) | import("math") | Used internally |
📊 Complete Properties Reference
| Function | Return Type | Default Behavior | Description | Compatibility |
|---|---|---|---|---|
| abs | int/float/complex | Returns absolute value | Mathematical absolute | All versions |
| all | bool | True for empty | Check all truthy | All versions |
| any | bool | False for empty | Check any truthy | All versions |
| ascii | str | Escapes non-ASCII | ASCII-safe repr | 3+ |
| bin | str | Binary string | Convert int to binary | All versions |
| bool | bool | False for empty/zero | Type conversion | All versions |
| breakpoint | None | Invokes pdb | Enter debugger | 3.7+ |
| bytearray | bytearray | Empty if no source | Mutable bytes | All versions |
| bytes | bytes | Empty if no source | Immutable bytes | All versions |
| callable | bool | Check callability | Detect if callable | All versions |
| chr | str | Unicode char | Int to character | All versions |
| classmethod | classmethod | Wraps method | Bind to class | All versions |
| compile | code | Compiles src | Generate code obj | All versions |
| complex | complex | Create from args | Complex numbers | All versions |
| delattr | None | Deletes attribute | Remove attribute | All versions |
| dict | dict | Empty dict | Create dictionary | All versions |
| dir | list | Attributes | Introspect object | All versions |
| divmod | tuple | Quotient, remainder | Div and mod | All versions |
| enumerate | enumerate | Index, value | Enumerate iterable | All versions |
| eval | Any | Evaluate expr | Dynamic evaluation | All versions |
| exec | None | Executes code | Dynamic execution | All versions |
| filter | iterator | Filter by func | Filter iterable | All versions |
| float | float | 0.0 default | Convert to float | All versions |
| format | str | Formats value | Apply format spec | All versions |
| frozenset | frozenset | Empty default | Immutable set | All versions |
| getattr | Any | Raise if missing | Get attribute | All versions |
| globals | dict | Current globals | Return globals | All versions |
| hasattr | bool | False if missing | Check attribute | All versions |
| hash | int | Hash value | Hashable objects | All versions |
| help | None | Interactive | Help system | All versions |
| hex | str | Hex string | Int to hex | All versions |
| id | int | Unique id | Object identity | All versions |
| input | str | Prompt optional | Read user input | All versions |
| int | int | 0 default | Convert to int | All versions |
| isinstance | bool | Check instance | Type check | All versions |
| issubclass | bool | Check subclass | Class hierarchy | All versions |
| iter | iterator | Create iterator | Return iterator | All versions |
| len | int | Object length | Size of container | All versions |
| list | list | Empty list | Create list | All versions |
| locals | dict | Current locals | Return locals | All versions |
| map | iterator | Apply func | Transform iterable | All versions |
| max | Any | Find max | Largest element | All versions |
| memoryview | memoryview | View object | Buffer interface | All versions |
| min | Any | Find min | Smallest element | All versions |
| next | Any | Next item | Iterator consumption | All versions |
| object | object | Base obj | Root of hierarchy | All versions |
| oct | str | Octal string | Int to oct | All versions |
| open | file object | Text read mode | Open file | All versions |
| ord | int | Unicode code | Char to int | All versions |
| pow | int/float | Exponentiation | Power with mod | All versions |
| None | Output to stdout | Print objects | All versions | |
| property | property | Manage attr | Encapsulation | All versions |
| range | range | Empty default | Immutable sequence | All versions |
| repr | str | Unambiguous repr | Debug string | All versions |
| reversed | iterator | Reverse sequence | Iterator reverse | All versions |
| round | int/float | Round to int | Round value | All versions |
| set | set | Empty set | Mutable set | All versions |
| setattr | None | Assign attr | Dynamic set | All versions |
| slice | slice | Start/stop/step | Slice object | All versions |
| sorted | list | Ascending | Sort iterable | All versions |
| staticmethod | staticmethod | Wraps method | No self/cls | All versions |
| str | str | Empty string | Create string | All versions |
| sum | int/float | Start=0 | Sum iterable | All versions |
| super | super | Access parent | Delegate calls | All versions |
| tuple | tuple | Empty tuple | Immutable sequence | All versions |
| type | type | Return type | Dynamic class | All versions |
| vars | dict | dict | Object attributes | All versions |
| zip | iterator | Aggregate tuples | Parallel iteration | All versions |
| import | module | Import module | Dynamic import | All versions |
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