Python Basics---->python Use (vii)

Here is a note of Python's knowledge of Io, adorners, and serialization. the face of the river I am infinitely ashamed, I wasted time, empty a tired, and all the dream for the horse as a poet, the years are easy to die a drop not left.

Some knowledge of Python one, the use of adorners in Python

Print a word before calling the now function, @log placed above the definition of the function.

deflog (func):defWrapper (*args, * *Kwargs):Print('Call %s ():'% func.__name__)        returnFunc (*args, * *Kwargs)returnWrapper@logdefNow ():Print('2017-12-12') Now ()Print(now.)__name__)

The results of the operation are as follows:

Call Now (): -wrapper 

If you need to pass parameters in the adorner, you need to nest more layers outside.

deflog (text):defDecorator (func):defWarpper (*args, * *Kwargs):Print('%s%s ():'% (text, func.)__name__))            returnFunc (*args, * *Kwargs)returnWarpperreturnDecorator@log ('Hello World')defNow ():Print('2017-12-12') Now ()Print(now.)__name__)

The results of the operation are as follows:

Hello World Now (): -warpper 

The above two kinds of now.__name__ changed to Warpper, a complete example is as follows:

Import Functools def log (func):    @functools. Wraps (func)    def Wrapper (*args, * *kw)        :Print ('call%s ():' % func.  __name__)        return func (*args, * *kw    )return Wrapper

Import Functools is importing the Functools module. The concept of the module is explained later. Now, just remember to add @functools.wraps (func) in front of the definition wrapper ().

Second, the use of partial function in Python

#use of partial functionsPrint(Int ('12345', base=8))Print(Int ('12345', base=16))#In This we define a binary function.defInt2 (x, base=2):    returnInt (x, base)Print(Int2 ('100101010'))#298#with the partial function, the parameters of a function can be fixed directlyImportFunctoolsint2= functools.partial (int, base=2)Print(Int2 ('101001010'))# the

Iii. use of Stringio and Bytesio

 fromIoImportstringiof=Stringio () f.write ('Hello') F.write (' World')Print(F.getvalue ())#Hello World#read the Stringio dataf = Stringio ('Hello!\nhi!\ngoodbye') whiletrue:s=F.readline ()ifs = ="':         Break    Print(S.strip ())#Stringio can only operate STR, if it is binary data, it is necessary to use Bytesio fromIoImportbytesiof=Bytesio () f.write ('English'. Encode ('Utf-8'))Print(F.getvalue ())

The results of the operation are as follows:

Hello Worldhello! Hi! Goodbyeb ' \xe4\xb8\xad\xe6\x96\x87 '

Iv. module OS operating directory and files in Python

#name of the systemImportOSPrint(Os.name)#Environment VariablesPrint(Os.environ)Print(Os.environ.get ('Java_home'))#operation of files and directoriesPrint(Os.path.abspath ('.'))#G:\Java\Go\program\2017-05-18\LearnPython1\test10\ioPrint(Os.path.join ('C:/users/michael','TestDir')) Os.mkdir (Os.path.join ('C:/users/michael','/testdir'))#get the directory and file name of the filedirectory, filename = Os.path.split ('/users/michael/testdir/file.txt')Print(directory)Print(filename)#get the suffix of the filePrint(Os.path.splitext ('/path/to/file.txt') [1])#. txt#modify file names and delete filesOs.rename ('Test.txt','test.py') Os.remove ('test.py')#Copying of filesImportShutilshutil.copyfile ('/user/huhx.txt','/user/linux.txt')

V. Serialization in Python

ImportPickled= Dict (name='Huhx', Age=20, score=80)Print(Pickle.dumps (d))#B ' \x80\x03}q\x00 (x\x04\x00\x00\x00nameq\x01x\x04\x00\x00\x00huhxq\x02x\x03\x00\x00\x00ageq\x03k\x14x\x05\ X00\x00\x00scoreq\x04kpu. '#Serialization off = open ('Dump.txt','WB') Pickle.dump (d, f) f.close ()#deserializationf = open ('Dump.txt','RB') d=pickle.load (f) f.close ()Print(d)#{' name ': ' Huhx ', ' age ': ' Score ':ImportJSONPrint(Json.dumps (d))#{"name": "Huhx", "age": +, "score":Json_str='{"Age": +, "score": "," "Name": "Bob"}'Print(Json.loads (JSON_STR))#{' age ': ' Score ': ' The ' name ': ' Bob '}

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Python Basics---->python Use (vii)