Python3.9全部73個內置函式說明

1. all([True,True])==True
2. all([True, False])==False
3. all((True,[True]))==True
4. all(((False),True))==False

1. any([True,False])==True
2. any((False,False))==False
3. any([(True),False])==True
4. any([False,(False)])==False
5. any(((False),[True]))==True

ascii(x)

1. ascii('123中國')=="'123\\u4e2d\\u56fd'"
2. ascii('abc\txyz')=="'abc\\txyz'"
3. len(ascii('abc'))==5
4. ascii(123.456)=="123.456"
5. ascii(3>2) == "True"

bin(x)

1. bin(12)=='0b1100'
2. bin(64)=='0b1000000'
3. bin(0xAB)=='0b10101011'

bool(x)

1. bool(0)==False
2. bool(-1.23)==True
3. bool('abc')==True
4. bool('False')==True
5. bool('')==False
6. bool([])==False
7. bool([0])==True
8. bool({})==False
9. bool((0))==False
10. bool((0,))==True

breakpoint(*args, **kwargs)

bytearray(x, ec)

bytearray('abc中國', 'utf-8')==b'abc\xe4\xb8\xad\xe5\x9b\xbd'

bytes(x, ec)

b'abc\xe4\xb8\xad\xe5\x9b\xbd'

callable(x)

1. callable(123)==False
2. callable(abs)==True
3. callabel(lambda: 12)==True

chr(x)

1. chr(65)=='A'
2. chr(0x4e2d)=='中'

classmethod(func)

class ABC:

@classmethod

def mm(cls, p1, p2):

print(cls, p1, p2)

ABC.mm(p1=123, p2=456)

ss = compile( 
    'a=3+4\nprint(a)', 
    'error.txt', 'exec')
exec(ss)  # 列印7

complex(x)

copyright()

credits()

credits()

delattr(x, name)

dict(x)

dict((('a', 123), ('b', 456))) ==

{'a':123, 'b': 456}

1. dir()
2. dir(abs)
3. dir(str)
4. dir(123)
5. dir(True)
6. dir(numpy)

divmod(x, y)

enumerate(x)

for i, e in enumerate([10, 11, 12]):

print(i, e)

eval(x, globals=None, locals=None)

1. eval('1+2+3')==6
2. eval('a+6', {'a': 10}) == 16

exec(x, globals=None, locals=None)

1. exec('a = 1\nprint(a)') # 列印
2. exec('for e in ls:\n\tprint(e+a)', {'ls':[1, 2]}, {'a':10}) # 列印11和12

exit(x)

以錯誤碼x退出Python環境，0表示沒有錯誤

filter(func, xs)

filter(lambda a: a>3, [1,5,2,7]等價于(5,7)

float(x)

1. float(3)==3.0
2. float('123.45')==123.45
3. float(True)==1.0

format(obj, spec='')

frozenset(xs)

frozenset型別，frozenset與set的不同僅在于前者不能增加或者洗掉元素

getattr(obj, name)

globals()

hasattr(obj, name)

hash(obj)

hex(x)

1. hex(123)=='0x7b'
2. hex(789)=='0x315'

id(x)

1. id('abc')==140591343332848
2. id(True)==4332063440
3. id(123)==140591322433712
4. id(['a', 'b'])==140591347517376

input(prompt)

int(x)

1. int('123')==123
2. int(True)==1
3. int(3.6)==3
4. int(-3.6)==-3

isinstance(obj, t)

1. isinstance(123, int)==True
2. isinstance('abc', str)==True
3. isinstance(True, (str, bool, int))==True

issubclass(t1, t2)

1. issubclass(float, int)==False
2. issubclass(int, float)==False

iter(obj)

呼叫obj.__iter__()以獲得一個迭代器(Iterator)，迭代器是這樣一種物件，它的.__next__()函式被重定義了，因此可以用next()函式呼叫，生成器(Generator)就是一種迭代器，所有序列物件的.__iter__()已經被重定義

a = [11, 'abc']
a = iter(a)
print(next(a)) # 列印11
print(next(a)) # 列印abc
print(next(a)) #StopIteration

len(xs)

class A:
    def __len__(self):
        return 123
print(len(A()))  # 列印123

license()

list(x)

1. list((1, 2, 3))==[1, 2, 3]
2. list({1, 2, 3})==[1, 2, 3]
3. list({'a':1, 'b':2})==['a', 'b']

locals()

map(func, *iterables)

map(lambda a, b: a+b, [1, 2, 3], (10, 20 ,30))等價于(11, 22, 33)

1. max([1, 9, 7, 12]) == 12
2. max(['aaa', 'bb', 'c'])=='c'
3. max(['aaa', 'bb', 'c'], key=lambda a: len(a)) == 'aaa'

1. max(1, 9, 7, 12) == 12
2. max('aaa', 'bb', 'c')=='c'
3. max('aaa', 'bb', 'c', key=lambda a: len(a)) == 'aaa'

memoryview(bytes)

1. memoryview(b'abc')等價于(97, 98, 99)

1. min([1, 9, 7, 12]) == 1
2. min(['aaa', 'bb', 'c'])=='aaa'
3. min(['aaa', 'bb', 'c'], key=lambda a: len(a)) == 'c'

1. min(1, 9, 7, 12) == 1
2. min('aaa', 'bb', 'c')=='aaa'
3. min('aaa', 'bb', 'c', key=lambda a: len(a)) == 'c'

next(obj)

next(iter([1, 2, 3]))==1

object

oct(x)

1. oct(12)=='0o14'
2. oct(64)=='0o100'
3. oct(0xAB)=='0o253'

open(path, mode='r', buffering=-1, encoding=None)

1. ord('A')==65
2. ord('a')==97
3. ord('0')==48
4. ord('中')==20013

class A:

@property

def mm(self):

pass

a = A()

print(a.mm)

quit(code=0)

range(n)

repr(obj)

reversed(xs)

1. round(3.5)==4
2. round(-3.5)=-4
3. round(1.2345, 2)==1.23
4. round(1234.5, -2)==1200.0

1. set()=={}
2. set([1, 3, 2, 3]) == {1, 2, 3}
3. set({'a':1, 'b': 2})=={'b', 'a'}

setattr(obj, name, value)

slice(start, end, step=1)

a=slice(1, 9, 2)

b=[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

b[a]==[2, 4, 6, 8]

staticmethod()

1. str(123)=='123'
2. str(123.456)=='123.456'
3. str(True)=='True'
4. str([1,2,3])=='[1, 2, 3]'
5. str({1, 2, 3})=='{1, 2, 3}'
6. str((1))=='1'
7. str((1,))=='(1,)'
8. str({'a': 1, 'b': 2})=="{'a': 1, 'b': 2}"

super(cls, obj)

tuple(iterable)

type(obj)

vars(obj==None)