1. abs() takes absolute value
print(abs(-156)) # 156 print(abs(-15.2)) # 15.2
2,all() If all elements are true, the Boolean value true is returned. If the element is empty, it also returns true. Only one parameter can be entered, and two can not be placed. Generally, they are placed in the list, Yuanzu
Elements are True except for 0, empty, None and False, but even if only two '' are put here, something will output True
As long as there is a False element in the judged data, False is directly output
a = [0] print(all(a)) # False print(all('False')) # True
3. If any() is put into the ancestor or all element bits in the list, False will be output
a = [0,''] print(any(a)) # False
4. bin() converts decimal to binary
print(bin(10)) # 0b1010 print(bin(4)) # 0b100 print(bin(2)) # 0b10
5. bool() converts parameters to Boolean values, and outputs False if there are no parameters
print(bool(0)) # False print(bool(1)) # True print(bool()) # False
6. bytes() converts a string to byte form Convenient network transmission
name = 'Xin Qiji' print(bytes(name,encoding='utf-8')) # b'\xe8\xbe\x9b\xe5\xbc\x83\xe7\x96\xbe' print(bytes(name,encoding='utf-8').decode('utf-8')) # Xin Qiji
Here encoding='utf-8 'is the defined encoding, the first line is the definition encoding with UTF-8, and the second line. decode is decoding with UTF-8
7. The return value of chr() is the ASCII character corresponding to the current integer
print(chr(47)) # /
8. dir print view list of used releases
print(dir(all))
9. Divide the number of parameters in front of divmod by the quotient of the following parameters to obtain the remainder
print(divmod(10,7)) # (1, 3)
Shang 1 Yu 3
10,eval()
1. Extract the data structure in the string
2. You can calculate the result of the mathematical operation formula inside the string
a = '1 + 3' print(eval(a)) # 4
11. hash() hashes the parameters passed in
Data types that can be hashed are immutable data types
A non hashable data type is a variable data type
The output length of hash operation is the same
The result before hash operation cannot be known through reverse operation
a = '44aa5556545' b = 'Flowers have a reopening day' c = 'No one is young again' print(hash(a)) print(hash(b)) print(hash(c))
The hash calculation results of each run are also different
12. The enumerate() function is used to combine a traversable data object (such as list, tuple or string) into an index sequence, and list data and data subscripts at the same time. It is generally used in the for loop. Define two variables at a time. The first is the index and the last is the data element
l = ('a','b','c','d','e','f','g','h','i','j','k','l') for x,i in enumerate(l): print(x,i)
x = 0 l = ('a','b','c','d','e','f','g','h','i','j','k','l') for i in l: x = x + 1 print(x,i)
The output of the above two codes is the same
13. Help displays help information
print(help(all))
14. hex 10 to hex
print(hex(18)) # 0x12
15. oct 10 to octal
print(oct(18)) # 0o22
16. id() prints the memory address of a thing
a = 15 print(id(a)) # 2587034479344
17. isinstance() determines whether the former is something defined by the latter, and outputs a Boolean value
print(isinstance(123,int)) # True
18,globals()
Print out the current global variable
print(globals())
19,locals()
Print all local variables
If it is running directly in the global, the global variables will be displayed directly
20. zip() function the zip function arranges the elements in the incoming elements one by one, and discards them all individually
print(list(zip(('aa','bb','cc'),(3,4,5)))) #[('aa', 3), ('bb', 4), ('cc', 5)] print(list(zip(('aa','bb','cc'),(3,4,5,6)))) #[('aa', 3), ('bb', 4), ('cc', 5)] print(list(zip(('aa','bb','cc','dd'),(3,4,5)))) #[('aa', 3), ('bb', 4), ('cc', 5)]
ziDian = {'name':'adam', 'nianLing':25,'shenGao':'185cm' } print(list(zip(ziDian.keys(),ziDian.values()))) #[('name', 'adam'), ('nianLing', 25), ('shenGao', '185cm')]
print(list(zip('1234567','abcdefg'))) #[('1', 'a'), ('2', 'b'), ('3', 'c'), ('4', 'd'), ('5', 'e'), ('6', 'f'), ('7', 'g')]
The zip function is mainly passed in Sequence type on-line list primitive string
21, max and min
Take the maximum and minimum values
Need to pass in iteratable data
Each bit of the element is compared in turn. If the first bit has obtained the maximum or minimum value, the next bit is not compared
Different types of data cannot be compared, such as str and int
max and min can be followed by key, that is, you can define the value that needs cyclic comparison, and take the elements associated with this value as a whole
#Find the tallest of the three ziDian1 = [ {'name': 'Zhang San', 'shenGao': 136}, {'name': 'Li Si', 'shenGao': 148}, {'name': 'Wang Wu', 'shenGao': 176} ] print(max(ziDian1,key =lambda a:a['shenGao'])) # {'name': 'Wang Wu', 'shenGao': 176}
22. ord() displays the value of the character in the asker code
print(ord('w')) # 119
23. pow() is the power of the second parameter of the first parameter. If there is a third parameter, the remainder of the calculation result of the former is taken
print(pow(3,3)) #3**3 print(pow(3,3,2)) #3**3%2
24. Reversed
a = [1,2,3,4] print(list(reversed(a))) # [4, 3, 2, 1]
25. round
print(round(3.5)) # 4
26. set as dictionary
print(set('adam')) # {'a', 'd', 'm'}
27. Slice defines slice width and step size
a = 'abcdefgh' b = slice(3,6) c = slice(3,6,2) print(a[3:6]) # def print(a[b]) # def print(a[c]) # df
c here is to set the step size to 2, so the slice extraction is to extract from the third bit, that is, the letter d, and then empty a bit to f and then go in and extract
28. Sorted
a = [6,3,2,4,8,9] print(sorted(a)) #Height ranking ziDian1 = [ {'name': 'Zhang San', 'shenGao': 136}, {'name': 'Li Si', 'shenGao': 189}, {'name': 'Wang Wu', 'shenGao': 176} ] print(sorted(ziDian1,key =lambda a:a['shenGao']))
Followed by the parameter key, that is, the extraction sort is arranged according to the value corresponding to the shenGao key in the dictionary
Sequential arrangement
29. sum
l = [4,5,6] print(sum(l)) # 15
30. View data type
a = 'qsx' print(type(a),a) # <class 'str'> qsx
31. When vars is inside the function, if no parameter is filled in, locals is the local variable
If the parameter is written, the method of using the function is listed and output in the form of a dictionary
32. The import module is other py files. You can write the file name of Py directly here without adding. Py
When called, write py file name directly followed by . And the required function name
__ import__ () this py file name that can import string type is recommended because it is used at the bottom