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function A function is a code segment that implements a certain function. It passes in parameters and returns values. Python built-in function len, pass it a list, and it will return the length of the list (return value); The print function prints the incoming object to the screen. It does not return any value. We say it returns None; The ret ...

Tip: after the article is written, the directory can be generated automatically. Please refer to the help document on the right for how to generate it preface Scrapy crawler's website image crawling Scripy crawls the link to the website's training pictures Tip: the following is the main content of this article. The following cases c ...

Recently, because of the great innovation, I began to learn machine learning. In the process of learning decision tree, I saw the related operations of decision tree visualization. Firstly, the tree object of sklearn library is used for tree building and model training: from sklearn import tree # Establish decision tree classifier dtc = t ...

preface How to make statistical analysis for multiple band values? You can use the reduceRegions function Image.reduceRegions(collection, reducer, scale, crs, crsTransform, tileScale) Apply the reducer on the area of each feature in a given set. The input number of reducer must be the same as the number of bands of the input image. Return t ...

1. The whole story One cool afternoon, I saw a news that the interface was being mechanically called. I suspected that someone was using script to brush the interface (mainly to divert water from the platform). what? No, the general interface request is encrypted. Unless you know the encryption key and encryption method, the call will not ...

preface   we explained the functions in Python in detail through three articles, including How to write functions,How to pass arguments as well as How to use arguments and keyword arguments . Starting from this article, I'll introduce you to classes in Python. First, I'll introduce you to create and use classes. 1, Create and use classe ...

environment The process in php is completed in the form of extension. Through these extensions, we can easily complete a series of actions of the process. pcntl extension: the main process extension, which completes the process creation in the waiting operation. posix extension: complete the general api of posix compatible machine, such as ob ...

Python sequence (list and tuple) usage complete introduction The so-called sequence refers to a sequence containing multiple data data structure , the sequence contains multiple data items (also known as members) arranged in order, and the members can be accessed through the index. Common sequence types in Python include strings, lists, and tu ...

ThreadLocal is literally translated as "thread local" or "local thread". If you really think so, you are wrong! In fact, it is a container for storing local variables of threads. I think it should be called ThreadLocalVariable (thread local variable) is right. I really don't understand why the engineers of Sun company named ...

Two files, cards_main.py and cards_ tools. py. The functions realized include adding business cards, displaying all business cards and querying business cards. General idea: First, edit the main function to determine the functions in the main function. After the file needs to be executed, the menu function show is displayed directly_ Menu fu ...