Simple use and introduction of Python built-in functions

"""
Simple use and introduction of built-in functions
Reference Link: https://docs.python.org/3/library/functions.html

"""
1.
ABS ()  # Absolute Value
"""

n = ABS ( -10) print (n) # 10

"""
2.
All ()   # is true, output ture, output flase
Any ()   # As long as there is true, output ture, then output flase

0,none, "", [], (), {}  # False
"""

N1 = ALL ([1,2,3,[],none]) print (n1) # Falsen2 = Any ([1,0, "", []]) print (n2) # True

　　

"""
3.
ASCII ()
__repr__ method for automating object execution
"""

Class Foo:    def __repr__ (self):        return "444" n = ASCII (Foo ()) print (n) # 444

　　

"""
4.
Bin ()  # Convert decimal to binary 0b to  indicate binary
Oct ()  # Convert decimal to octal  0o for octal
Hex ()  # Convert decimal to hexadecimal  0x for hexadecimal
"""

Print (Bin (5)) Print (Oct (9)) print (hex) # 0b101# 0o11# 0x1b

　　

"""
5.
BOOL ()  Boolean value
0,none, "", [], (), {}  = False
"""


"""
6.
Bytes ()
UTF8 encoding, 3 bytes of a kanji
GBK encoding, 2 bytes of a kanji
One byte = = 8 bits

STR ()
Bytes into a string
"""

# Converts a string to a byte type, with a representation of 16 in the system # Bytes (string, encoded format) s = "China" n3 = bytes (s,encoding= "Utf-8") print (n3) # B ' \xe4\xb8\xad\xe5\x9b\ Xbd ' N4 = bytes (s,encoding= "GBK") print (N4) # b ' \xd6\xd0\xb9\xfa ' N5 = str (b ' \xd6\xd0\xb9\xfa ', encoding= "GBK") print (N5) # China N6 = str (b ' \xe4\xb8\xad\xe5\x9b\xbd ', encoding= "Utf-8") print (N6) # China

　　

"""
7.
Callable ()
Detects whether the passed value can be called
"""

Def f1 ():    passf1 () F2 = 123print (callable (F1)) # Trueprint (callable (F2)) # False

　　

"""
8.
Chr ()
Ord ()
Output ASCII correspondence, Chr () output decimal position character, Ord () output character in ASCII table position
"""

Print (CHR) # Aprint (Ord ("A")) # 65# instance 1: Generate 6-digit random password, plain letter # import random# li = []# for I in range (6): #     temp = chr (rand Om.randrange (65,91) #     Li.append (temp) # print (LI) # result = "". Join (LI) # print (Result) # instance 2: Generate 8-digit random password with a number,  The letter Import Randomli = []for i in range (8):    r = Random.randrange (0,6)   # Let's generate the position of the number random    if r = = 2 or r = = 5:        num = Random.randrange (0,10)        li.append (num)    else:        temp = Random.randrange (65,91)        c = chr (temp)        Li.append (c) result = "". Join (LI) print (result) # 3e4jvhf8

　　

"""
9.
Compile ()   # Compile, compile the string into Python code
eval ()      # executes an expression and gets the result
EXEC ()      # Execute Python code

Note: Eval has a return value, exec does not return a value
Python hello.py process:
    1. read file contents open,str to memory
    2.python, String----Compile special code
    3. Execute code
"""

s = "Print (' hello,python~ ')" R = Compile (s, "<string>", "exec") exec (r) # hello,python~ss = "8*8+5" Print (eval (ss)) # 69

　　

"""
10.
Dir ()
Help ()
Quick access to module, object-provided functionality
"""

Print (dir (tuple)) print (Help (tuple))

　　

"""
11.
Divmod ()
Get quotient and remainder
"""

N1,N2 = Divmod (96,10) print (N1,N2) # 9 6

"""
12.
Isinstance ()
Used to determine whether an object is an instance of a class
"""

S1 = "Hello" r = isinstance (s1,str) print (r) # Truer1 = isinstance (s1,list) print (R1) # Flase

　　

"""
13.
The filter ()    # function returns a value of ture, adding the element to the result
            # filter Loop second parameter, let each loop element execute function, if function return value is ture, the function is valid
Map ()       # Adds a function return value to the result
            # (Functions, objects that can be iterated (for loops))
"""

# example 1def F1 (args): result = [] for item in ARGS:IF item > 22:result.append (item) return RE        Sultli = [11,22,33,44,55,66,77,88]ret = f1 (LI) print (ret) # [33, 44, 55, 66, 77, 88]# optimization Example 1def F2 (a): If a > 22:  return TRUELS1 = [11,22,33,44,55,66,77]res1 = Filter (F2,LS1) print (list (res1)) # [33, 44, 55, 66, 77]# knowledge extension, lambda function res2 = Filter (lambda x:x > 22,ls1) print (RES2) # Returns a filter object# <filter object at 0x000000e275771748>print (list ( RES2) # [33, 44, 55, 66, 77]# example 2def F1 (args): result = [] for i in args:result.append (i +) return re    Sultlst1 = [11,22,33,44,55,66]rest = f1 (lst1) print (list (rest) # [111, 122, 133, 144, 155, 166]# optimization example 2,,,map function def f2 (a): Return a + 100lst2 = [11,22,33,44,55,66]RESULT1 = map (f2,lst2) Print (list (RESULT1)) # [111, 122, 133, 144, 155, 166]# optimization shown Example 2,map function +lambda function lst3 = [11,22,33,44,55,66]RESULT2 = map (lambda a:a+100,lst3) print (list (RESULT2)) # [111, 122, 133, 144, 155, 166]

 
 
 
 "" "
   .    
 Globals () # All global Variables 
 Locals () # All local variables 
 "" 

name = "Python" def Show (): a = 123 b = 456 print (locals ()) Print (Globals ()) show () # {' A ': 123, ' B ': 456}# {' r Esult ': ' 3vz8b1v0 ', ' res1 ': <filter object at 0x000000ecfe24b5c0>, ' lst3 ': [One, one, one, one, one, one, one], ' __package__ ': None, ' F2 ': <function F2 at 0x000000ecffcb9268>, ' ss ': ' 8*8+5 ', ' N2 ': 6, ' n3 ': B ' \xe4\xb8\xad\xe5\x9b\xbd ', ' temp ':  The ' s1 ': ' Hello ', ' n ': ' 444 ', ' name ': ' Python ', ' I ': 7, ' rest ': [111, 122, 133, 144, 155, 166], ' __spec__ ': None, ' lst1 ': [One, one, one, one, one, one, and a, ' R1 ': False, ' num ': 0, ' __builtins__ ': <module ' builtins ' (built-in), ' N6 ': ' China ', ' Rando M ': <module ' random ' from ' c:\\users\\xieshengsen\\appdata\\local\\programs\\python\\python35\\lib\\random.py ' , ' s ': ' Print (' hello,python~ ') ', ' __file__ ': ' d:/pycharmprojects/Advanced Automation/Module learning/built-in function _v1.py ', ' F1 ': <function F1 at 0x000000ecffcbf510>, ' result2 ': <map object at 0x000000ecfe25ec88>, ' Show ': <function show at 0x000000ecffcbf2f0>, ' ret ': [33, 44, 55, 66, 77, 88], ' __cached__ ': None, ' li ': [One, one, one, one, one, one, one, one], ' __doc__ ': ' \ n simple use and introduction of built-in functions \ n Reference Links: HTTPS://DOCS.PYTHON.ORG/3 /library/functions.html\n ', ' C ': ' V ', ' result1 ': <map object at 0x000000ecfe260d30>, ' Foo ': <class ' __main__. Foo ';, ' N1 ': 9, ' N5 ': ' China ', ' r ': True, ' __loader__ ': <_frozen_importlib_external. Sourcefileloader object at 0x000000ecfdfea898>, ' LS1 ': [One, one, one, one, one, one, 22], ' lst2 ': [11, 33, 44, 55, 66], ' Res2 ': <filter object at 0x000000ecfe24b4a8>, ' N4 ': B ' \xd6\xd0\xb9\xfa ', ' __name__ ': ' __main__ '}

"""
15.
Hash ()
Generate a hash value (string)
"""

has = "python" Print (a hash (has)) # 839578881833832098

　　

"""
16.
Len ()
The length of the output object
"""

Print (len ("Python")) # 6print (Len ("Great Wall")) # Python3,  python2 output length is 6 (python3 by character, Python2 by Byte) # 2

　　

"""
17.
Max ()  # max value
Min ()  # Minimum value
Sun ()  # summation
"""

lit = [11,22,33,44,55]print (max (lit)) print (min (lit)) print (sum (lit)) # 55# 11# 165

　　

"""
18.
POW ()
Seeking Index
"""

Print (POW (2,10)) # 1024

　　

"""
19.
Reverse ()
Reverse
"""

Lit1 = [11,22,33,44,55,66]print (list (Reversed (LIT1)) # [66, 55, 44, 33, 22, 11]

　　

"""
20.
Round ()
Rounding evaluation
"""

Print (round (1.4)) Print (round (1.8)) # 2

　　

"""
21st.
Sorted ()
Sort that is equivalent to a list
"""

Lit2 = [12,32,1,3,4,34,11,5]print (list (sorted (lit2))) # [1, 3, 4, 5, one, a, 1, 34]lit2.sort () print (LIT2) # [3, 4, 5,, 11, 12, 32, 34]

"""
22.
Zip ()
"""

L1 = ["Hello", 11,22,33]l2 = ["World", 44,55,66]l3 = ["Python", 77,88,99]l4 = Zip (l1,l2,l3) # Print (List (L4)) # # [(' Hello ', '  World ', ' Python '), (one, one, one, one, one, one), (+, (),]TEMP1 = List (l4) [0]print (temp1[0]) Ret1 = "". Join (TEMP1) print (ret1) # Hello World python

　　

Simple use and introduction of Python built-in functions