Python Built-in Functions Overview and Usage

Python provides a set of built‑in functions that can be used directly without importing any modules. Up to version 3.6.2 there are 68 built‑in functions, which are listed below.

Full list of 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()         delattr()
hash()          memoryview()    set()

Numeric‑related functions

Data types : bool(), int(), float(), complex() Base conversion : bin(), oct(),

hex()

print(bin(10))   # binary: 0b1010
print(hex(10))   # hexadecimal: 0xa
print(oct(10))   # octal: 0o12

Mathematical operations : abs(), divmod(), round(), pow(), sum(), min(),

max()

print(abs(-2))               # 2
print(divmod(20, 3))        # (6, 2)
print(round(4.50))          # 4
print(round(4.51))          # 5
print(pow(10, 2, 3))        # (10**2) % 3 => 1
print(sum([1,2,3,4,5,6,7,8,9,10]))  # 55
print(min(5,3,9,12,7,2))    # 2
print(max(7,3,15,9,4,13))   # 15

Data‑structure‑related functions

Sequences : list(),

tuple()

print(list((1,2,3,4,5,6)))   # [1, 2, 3, 4, 5, 6]
print(tuple([1,2,3,4,5,6]))   # (1, 2, 3, 4, 5, 6)

Sequence utilities : reversed(),

slice()

lst = "你好啊"
it = reversed(lst)          # returns an iterator, original unchanged
print(list(it))            # ['啊', '好', '你']
lst = [1,2,3,4,5,6,7]
print(lst[1:3])            # [2, 3]
s = slice(1,3,1)
print(lst[s])              # [2, 3]

String conversion :

str()

print(str(123) + '456')    # 123456

Collections : dict(), set(),

frozenset()

my_dict = dict(a=1, b=2)
my_set = set([1,2,3])
my_frozen = frozenset([1,2,3])

Collection utilities : len(), sorted(), enumerate(), all(), any(),

zip()

lst = [5,7,6,12,1,13,9,18,5]
lst.sort()
print(lst)                 # [1,5,5,6,7,9,12,13,18]
print(sorted(lst, reverse=True))  # [18,13,12,9,7,6,5,5,1]

# enumerate with start index 1
for idx, el in enumerate(['one','two','three','four','five'], 1):
    print(idx, el)

print(all([1, 'hello', True, 9]))   # True
print(any([0,0,0,False,1,'good']))  # True

lst1 = [1,2,3,4,5,6]
lst2 = ['A','B','C','D','E','F']
lst3 = ['US','CN','FR','IT','KR','JP']
for el in zip(lst1, lst2, lst3):
    print(el)

Scope‑related functions

locals()

– returns a dictionary of the current local symbol table. globals() – returns a dictionary of the current global symbol table.

def func():
    a = 10
    print(locals())   # {'a': 10}
    print(globals())  # large dict with module globals
    print("今天内容很多")
func()

Iterator and generator utilities

range()

– generates arithmetic sequences. iter() and next() – obtain an iterator and advance it.

for i in range(15, -1, -5):
    print(i)   # 15 10 5 0
lst = [1,2,3,4,5]
it = iter(lst)
print(next(it))   # 1
print(next(it))   # 2

Executing code from strings

eval()

– evaluates an expression and returns its value. exec() – executes statements; returns None. compile() – compiles source code to a code object for later execution.

s1 = input("请输入 a+b:")   # e.g. 8+9
print(eval(s1))               # 17
s2 = "for i in range(5): print(i)"
exec(s2)                     # prints 0‑4

code1 = "for i in range(3): print(i)"
com = compile(code1, "", mode="exec")
exec(com)                    # 0 1 2

code2 = "5+6+7"
com2 = compile(code2, "", mode="eval")
print(eval(com2))            # 18

Input/Output

print("hello", "world", sep="*", end="@")   # hello*world@

Memory‑related utilities

hash()

– returns the hash value of an immutable object. id() – returns the memory address of an object.

s = 'alex'
print(hash(s))   # e.g. -168324845050430382
print(id(s))     # e.g. 2278345368944

File operations

f = open('file', mode='r', encoding='utf-8')
content = f.read()
f.close()

Module handling

# Dynamically import a module entered by the user
import os
name = input("请输入你要导入的模块:")
__import__(name)

Help and introspection

print(help(str))   # shows documentation for the str type

Callable check

a = 10
print(callable(a))   # False

def f():
    print("hello")
print(callable(f))   # True

Attribute listing

print(dir(tuple))   # list of tuple methods

This article consolidates the 68 built‑in functions into twelve logical groups, providing concise explanations and ready‑to‑run code snippets so that beginners can quickly reference and practice Python fundamentals.