Python3 Built-in Functions

Python provides a large number ofBuilt-in Functions, which can be used directly without importing any libraries. These functions coverdata type conversion, mathematical computation, iteration operations, reflection mechanismsand other common scenarios, and are essential tools that every Python beginner must master.

Why should you master built-in functions?

  • Reduce code volume: one line replaces multiple lines (for examplesum()、max()）
  • Improve readability: clear semantics, clearer than hand-written logic
  • Better performance: implemented in C at the underlying level, usually faster than Python loops

Common Categories

  • Numerical computation:abs()、round()、min()、max()、sum()

  • Type conversion:int()、float()、str()、list()、tuple()

  • Iteration and functional:code>map()、filter()、zip()、enumerate()

  • Reflection and objects:type()、isinstance()、getattr()、setattr()

  • Input/Output:print()、input()、open()

Common Function Examples

# 求和
sum([1, 2, 3])  # 6

# 最大值
max([3, 6, 2])  # 6

# 类型转换
int("123")      # 123

# 枚举
for i, v in enumerate(['a', 'b']):
    print(i, v)

# map
list(map(lambda x: x * 2, [1,2,3]))  # [2,4,6]

Function Quick Reference Table

Search box
Built-in Functions
abs() dict() help() min() setattr()
all() dir() hex() next() slice()
any() divmod() id() object() sorted()
ascii() enumerate() input() oct() staticmethod()
bin() eval() int() open() str()
bool() exec() isinstance() ord() sum()
bytearray() filter() issubclass() pow() super()
bytes() float() iter() print() tuple()
callable() format() len() property() type()
chr() frozenset() list() range() vars()
classmethod() getattr() locals() repr() zip()
compile() globals() map() reversed() __import__()
complex() hasattr() max() round() reload()
delattr() hash() memoryview() set()
Other Extensions