more python programming for absolute beginner

Beginner Python , try to change the program that was previously written in C on the Raspberry Pi. Python version of the. Four-bit common yin digital tube and Raspberry Pi Circuit connection method is as follows:A ~ p-------------------------------GPIO0 ~ GPIO7D1 ~ d4-----------------------------GPIO11 ~gpio8Here is the photo after the circuit is connected:After c

!Of course, the actual code must not be written like this, this is to illustrate the function name is also a variable . To restore abs The function, restart the Python interactive environment.Note: Since the abs function is actually defined in __builtin__ the module, it is necessary __builtin__.abs = 10 to make the modified ABS point to the other modules .So when we write the program, this variable name can not be casually up!Second: higher-order fun

fileImport osdef init (func): Def wrapper (*args, **kwargs): G = func (*args, **kwargs) Next (g) return G Return wrapper# First stage: Find the absolute path to all files @initdef search: While True:filepath = yield g = os.walk (file Path) for Pardir, _, files in g:for file in Files:abspath = R '%s\%s '% (pardir, file) Target.send (abspath) # Search (R ' C:\Users\Administrator\PycharmProjects\python18 weekend Class \day5\aaa ') # G=sea

parameter sizhint represents the maximum word size returned.Output:1. Write (): writes a string containing text data or binary data blocks to a file. 2, Writelines (): For the list operation, accept a list of strings as parameters, write them to the file, the line terminator is not automatically added, if necessary, you must call the Writelines method before the end of each line to add a terminator. When reading rows from a file using read () or readlines (),

Python functional programming: higher-order functions, Map/reduce1 #function-type programming2 #one feature of functional programming is that it allows the function itself to be passed as a parameter to another function, and also allows a function to be returned3 #(i) Higher order functions4 5f=ABS6 F7 Print(F (-20))8 #Results9 #A function can assign a value to a

One, OS platform programming requirements1. Operation of directory filesHow to manipulate the system directory and file2, the timing of the implementation of the program3, the conversion of the executable programThe conversion of a Python program to an executable programSecond, the directory file operationRoot: current directory;Dirs: Folders in the current directoryFiles: File name under current directory1

4. Functional Programming 4.11 Advanced functionsMap receives 2 parameters, one is the function object itself, and the other is iterableList (map (str, [1, 2, 3, 4, 5, 6, 7, 8, 9]))# #reduce把结果继续和序列的下一个元素做累积计算def f (x):... return x * xReduce (f, [X1, x2, X3, x4]) = f (f (f (x1, x2), x3), x4)--------------------------------------> From functools Import reduce>>> def fn (x, y):... return x * ten + y...>>> def char2num (s):... return {' 0 ': 0, ' 1 ': 1,

Python folder and file operationsWe often deal with files and directories, and for these operations, Python can use the OS and Shutill modules, which contain many functions for manipulating files and directories. This way, only the methods that are commonly used are described.The OS can manipulate simple folders and file operations, introduce the import os, use the Help (OS) or dir (OS) to see its usage. N

- Isfile () specifies whether the path exists and is a file + Islink () specifies whether the path exists and is a symbolic link - Ismount () specifies whether the path exists and is a mount point +Samefile () Two path names pointing to the same file4. File related modules1Base64 provides the encoding between the binary string and the text stringdecoding Operation2BINASCII provides the encoding between binary and ASCII encoded binary stringsdecoding Operation3 BZ2A Accessing compressed files in

recommended to import with absolute path, not recommended with relative pathTry to avoid wildcard imports, such as using as little as possible *4 about namingModule names all use lowercase letters and underline to increase readabilityThe name of the package is the same as the module, but the package is best not underlinedClass name, first letter capitalization, using hump notationfunction name, use all lowercase lettersGlobal variables, all in upperc

#! Python3#Import modules and write comments to describe.Importzipfile, Os fromPILImportImage fromPILImportImageFile#os.chdir (' d:\\my documents\\ ')Imagefile.load_truncated_images =True forFolderName, subfolders, filenamesinchOs.walk ('d:\\my documents\\'): Numphotofiles=0 Numnonphotofiles=0 forFileNameinchFilenames:#Check if file extension isn ' t. png or. jpg. if not(Filename.endswith ('. PNG')orFilename.endswith ('. jpg') orFilename.endswith ('. PNG')orFilename.endswith ('. JPG'

Higher order functions: functions that accept functions as arguments are higher-order functionsfunction as a parameter to find the absolute value.def add (x, Y, f):return f (x) +f (y)Add ( -5, 9, ABS)1). Map () is a Python built-in high-order function that receives a function f and a list, and then, by putting the function f on each element of the list in turn, gets a new list and returns.For example, for l

First, to talk about the hole encountered:1. Package references for Linux under:1 """2 The path structure is as follows:3 ./project4 ./bin5 ./api6 """7 #to reference the contents of apilib.py in the API directory under main.py in the bin directory8 ImportSYS9Sys.path.append (".. /")Ten fromApi.apilibImportFunc2. When running large system, the execution directory of the script that you initiated under/root is also/root, so pay attention to the absolute