python gui builder

IteratorsAn object that can directly act on a for loop is called an iterative object (iterable).An object that can be called by the next () function and continually returns the next value is called an iterator (Iterator).All iterable can be converted to iterator via the built-in function iter ().names = ITER (['Sun','IBM','Sunny'])Print(names)Print(names.__next__())Print(names.__next__())Print(names.__next__())Print(names.__next__())#first output Print iterator object#the next method for the No.

There are several data in the process1 data that has been transferred received_size2 File Size TatolA = received_size/tatol B = a*100 where A is the percentage of data transferred, and B is the progress that has been transferred, with a total progress of 100Print now as soon as the implementation progress has been updated #1 #_*_coding:utf-8_*_2 #Author:jaye He3 Import Time4 5 6 defshow_progress (total):7Received_size = 0#received file size8current_percent = 0#Receive Progress9 whileRec

', ' Remove ', ' removedirs ', ' Rename ', ' Renames ', ' replace ', ' RmDir ', ' scandir ', ' Sep ', ' set_handle_inheritable ', ' set_inheritable ', ' spawnl ', ' Spawnle ', ' spawnv ', ' spawnve ', ' St ', ' Startfile ', ' stat ', ' stat_float_times ', ' stat_result ', ' statvfs_result ', ' strerror ', ' Supports_bytes_environ ', ' Supports_dir_fd ', ' supports_effective_ids ', ' supports_fd ', ' supports_follow_symlinks ', ' symlink ', ' sys ', ' system ', ' Terminal_size ', ' Times ', ' ti

With list generation, we can create a list directly. However, because of memory limitations, the listThe capacity is certainly limited. Also, create a list of 1 million elements that not only occupy aLarge storage space, if we just need to access the first few elements, then most of the elements behindThe space occupied is wasted. So, if the list element can be inferred by an algorithm, can we continue to extrapolate the subsequent elements in the process of looping? So you don't have toCreate a

,replace):d EF matches_rule (Word): Return Re.search ( Pattern,word) def apply_rule (word): return re.sub (Search,replace,word) return (matches_rule,apply_rule) rules = []with Open (' plural4-rules.txt ', encoding = ' utf-8 ') as Pattern_file:for line in pattern_file:pattern,search,replace = Line.split (none,3) rules.append (Build_match_and_apply_functions (pattern,search,replace))1) Open (): Opens the file and returns a file object.2) ' with ': Creates a context: when the With statement ends,

( ) Print (x.__next__ ()) print (x.__next__ ()) # known list L has 5 values, # is an exception when you take the 6th value stopiterationOutput Result:1Traceback (most recent):2 "c:/users/william/pycharmprojects/python_ item2/study/day9/iterator. Py" in print(x.__next__()) # known list L has 5 values,5stopiterationView CodeExample 2: Using Isinstance to determine whether a Python common data type is an iterator objectFrom collec

the For loop executes the third time only the print statement is executed10. Summary:The yield keyword features:与return的功能类似，都可以返回值，但不一样的地方在于一个函数中可以多次调用yield来返回值为函数封装好了`__iter__方法`和`__next__方法`，把函数的执行结果变成了迭代器`遵循迭代器的取值方式(obj.__next__())`,触发的函数的执行，函数暂停与再继续都由yield保存11. Example: Using yield to simulate a command in Linux: Tail-f | grep ' ERROR ' | grep ' 404 'The code is as follows:import timedef tail(file_path, encoding=‘utf-8‘): with open(file_path, encoding=encoding) as f: f.seek(0, 2)

Notes excerpt from: Https://www.liaoxuefeng.com/wiki/0014316089557264a6b348958f449949df42a6d3a2e542c000/ 0014317799226173f45ce40636141b6abc8424e12b5fb27000This article is only for oneself review use, Invasion deletes; List Builder For example, listing all the file and directory names in the current directory can be implemented in one line of code: Import for in Os.listdir ('. ')]#[4, 16, 36, 64, 100] for inch if x% 2 = =# Finally, all

Case: Tokens Builder Learning Essentials--random--string--string and digital synthesis exercises--ListToken generator ProgrammingAnalysis:import randomrandom.choice(‘acfhjlio‘) #随机选择一个字符‘f‘str_list=[‘a‘,‘b‘,‘c‘,‘d‘,‘e‘,‘2‘,‘3‘]s = ""s.join(str_list) #把列表中的字符串连接到s内，连接一起的意思‘abcde23‘s = ""for i in range(5): s = random.choice(‘adfjlui‘) print(s)lidiuimport stringstring.ascii_lowercase #表示26个小写字母‘abcdefghijklmnopqrstuvwxyz‘string.ascii_upper

List Builder is a very simple but very powerful built-in python.Generate a list [1,2,3,4] can use list (range (1,5))Application of List BuilderIf the above formula is judged, you can filter out the desired result, such as just the square of the even numberUsing multi-layer loopsGeneratorThe essential difference between a generator and a list generator is that one has generated data, and when used, it generates a memory overflow if the data is too larg

large chunk of memory in memory, #instead, each time the loop generates a #every time next time you give me a#Range#F#L = [1,2,3,45]#iterator = l.__iter__ ()#While True:#print (iterator.__next__ ())#Print (range (100000000000000))#Print (range (3))#Print (List (range (3)))#def func ():#For i in range (2000000):#i = ' wahaha%s '%i#return I#Generator-Iterator#Generator Functions--essentially, we write our own functions.#Builder Ex

stopiteration 3.itertools ModulePython's built-in module, Itertools, provides functions for manipulating iterative objects, which are convenient and practical. To give an example:I Slice (iterable, [Start,] stop [, step]):Creates an iterator that generates an item in a way similar to the slice return value: iterable[start:stop:step], skips the previous start item, iterates over the stop at the specified stop, and step specifies the stride used to skip the item. Unlike slices, negative va

execution process, encounter yield is interrupted, the next time continue to execute. After 3 yield, no yield can be executed, so the 4th call to Next () is an error.Returning to the FIB example, we constantly call yield during the loop, and we are constantly interrupted. Of course, you have to set a condition for the loop to exit the loop, or it will produce an infinite sequence.Similarly, after changing a function to generator, we basically never call it with next (), but instead use the For

recursive, then a layer of return;2. For stack frames in Python:The stack frame in Python is actually allocating memory on the interpreter's heap, so after a Python function is finished, its stack frame still exists and does not disappear, as shown in the following example (when the Func function is finished, we can then access its corresponding stack frame):Import Inspect def func (): ... Global x .

This example describes the Python builder generator usage. Share to everyone for your reference. Specific as follows: With yield, you can let a function generate a result sequence, not just a value For example: def countdown (n): print "Counting" while n>0: yield n #生成一个n值 Next () calls the generator function to run until the next yield statement, where next () passes the return value to yie

GeneratorThe function with yield is called generator (generator) in PythondefXragns ():#Defining function Generators Print('little Guy') yield('Good')#plus yield generates a generator Print('python') yield('Hao') Print('Programming') yield('Hao') x= Xragns ()#executing a function generator is just getting inside not executingret = x.__next__()#the next method of the generator will only execute the execution function to find the next

))Print('======>')Print(Next (g)) forIinchG:#I=iter (g) Print(i)　　Note : Whatis the comparison between yield and return? Same: function with return valueDifferent: Return only returns one value at a time, and yield can return multiple values2. Generator expression: similar to list derivation, however, the generator returns an object that produces results on demand, rather than building a list of results at a timeG= ('egg%s'%i forIinchRange (1000))Print(g)Print(Next (g))Print(Next (g))Print(Ne

So dict can use the for traversal key or values or key,valuesDict is an iterative object, depending on the use of the environmentHow do I get a list or a tuple to display subscripts and elements at the same time?Python provides the enumerate () function, which turns the list or tuple into: index-element pairs, like key-value pairst = [1,2,3,4,5] for in enumerate (t) print(k, '-', V)0-11-22-33-44-55-6List-GeneratedTo generate an L = [2,4,6,8,1

increase efficiency.The function that contains yield in Python is a generator (very likely)Yield is actually the same as return, except that a generator is returnedDefine a generatordef nub ():NUB = range (1,5)For I in NUB:Yield I*iThe type () can be used to see the nub of the function, and the function will run when the iteration (which can use Next ()), and the function will remain in the last run after each run, with an error when the iteration en

, can not change my - Core Function Name: Add to """ -There is a special function in Functools to deal with this problem.1 Import Time2 ImportFunctools3 4 5 deflog (now_time):6 defDeco (FN):7@functools. Wraps (FN)#add an adorner to the new function to modify the __name__ property of the new function8 defNew_func (*args, * *Kwargs):9 Print(now_time)Ten returnFN (*args, * *Kwargs) One returnNew_func A returndeco - - the @log (Time.asctime (Time.