dict comprehension python 3

:333} Set--DictMap 2 sets to a dictionary by Zip: 123456 Set1 = {1, 2, 3}Set2 = {' a ', ' B ', ' C '} print (dict (Zip (Set1, Set2)) # {1: ' C ', 2: ' A ', 3: ' B '} SETSTR, setThe characters are first cut into tuples and then converted to collections. 1 Print (Set (' Hello ')) # {' L ', ' o ', ' e

variable, which is actually a variable pointing to the function. A variable can point to a function, and the argument of a function can accept a variable. Then a function can receive another function as a parameter, which is called the higher order function. If you point a python built-in function name to another object, you cannot call the function through the variable name and error. The sample code is as follows: >>> ABS ( -10)10>>> abs in functio

, which is actually a variable pointing to the function.A variable can point to a function, and the argument of a function can accept a variable. Then a function can receive another function as a parameter, which is called the higher order function.If you point a python built-in function name to another object, you cannot call the function through the variable name and error. The sample code is as follows:>>> ABS ( -10)10>>> abs in function abs>>>> f

This blog collects the pits encountered from Python 2 to Python 3 due to different writing. Gives a written notation that Python 2 and Python 3 are compatible. 1. How to be compatible with raw_input () and input ()

Python Reading Notes-Chapter 3, chapter 4, python Reading NotesChapter 3 1. string formatting >>> format = "hello % s world" >>> values = ('World', 'hot ') >>> print format % values # You can also receive a single string or use the % f % d type. When matching multiple parameters with c's printf, you should use parenthe

There are a lot of python-specific things, very interesting, previously only contact C, C + +, Java, Javascript, did not expect to play like this#------------------Slice--------------------##slice slices to cut out another array from an arrayLi = List (range (10))Print(LI)#[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]#[Start, End, Step] | | (start-end) to be consistent with the sign of stepPrint(Li[2:5])#[2,

Python learning path 3: python learning pathContent of this section: Common string processing. Format the output string. String replacement. Conversion of strings and binary data. Dictionary operations String operation Common string processing Name = 'vector 'print (name. capitalize () # print (name. count ('E') # determine the number of print (name. cente

...1.In syntax, the return of a tuple can omit parentheses, and multiple variables can receive a tuple at the same time, assigned to the corresponding value by location,So, the Python function returns a multivalued value that actually returns a tuple, but it's easier to write.2.Defining default parameters Keep in mind that the default parameter must point to the immutable object!3.

differences between function parameter 3.2.1 C # And Python in function parameter definition There are four types of method parameters in C: (1) Value parameters do not contain any Modifier(2) The referenced parameter is declared with a ref modifier (there is no corresponding definition in Python)(3) output parameters are declared with the out modifier (this is

Python learning diary 3 variable 2, logical judgment, for loop, python variable Review the questions that occur when you write a quiz code. The condition in the While statement. It should be when result = false and answer = input. If answer = input () is written outside the while clause, too small will be output as it was yesterday. There is also the if statement

GET request#url = ' Http://xxxxxx/api/user/stu_info '#data = {' Stu_name ': ' xxxx '} #请求数据#req = requests.get (URL, params=data)#print (Req.json ())#print (Req.text)#print (Type (Req.json ())) #dict#print (Type (req.text)) #str#What's the return?#What is the returned type?#How does the Chinese do?#2. Post RequestURL ='Http://xxxxxxx/api/user/login'Data= {'username':'xxxxx','passwd':'xxxxx'}#Request Datareq =requests.post (URL, data)Print(Req.json ()

number Methods and descriptions 1 cmp (tuple1, tuple2) Compares two tuple elements. 2 len (tuple) The counts the number of tuple elements. 3 max (tuple) The returns the maximum value of the element in the Tuple. 4 min (tuple) The returns the minimum value of the element in the Tuple. 5 tup Le

modifiers(2) The reference parameter is declared with a ref modifier (there is no corresponding definition in Python)(3) Output parameters declared with out modifier (not required in Python, because functions can have multiple return values)(4) Array parameters are declared with the params modifierThere are also four types of function parameters in

Python [3]-dictionary dic And set, python dictionary dicsetI. dictionary dict Dict is stored as a key-value pair. The creation method is to use braces {} and separate the key and value with a colon. >>> d={'chen':60,'zhang':80}>>> print d{'chen': 60, 'zhang': 80} Assignment

(' blah ') Except (ValueError, Nameerror): Print ("Caught both types of exceptions") Example of an implicit exception chain in 2:python 3 Copy CodeThe code is as follows: Def divide (A, B): Try Print (A/b) Except Exception as exc: def log (exc): FID = open (' LogFile.txt ') # missing ' W ' Print (exc, file=fid) Fid.close () Log (EXC) Divide (1,0) 09. Dictionary D