watchdog generator

()) # Print (i.__next__ ()) # Print (i.__next__ ()) # Print (i.__next__ ()) #StopIteration　　　　Iterator determines whether an iterator object iterabl is required to iterate over the object as an iterative object. __iter__ () is converted to an iterator to iterate over an iterator object that can iterate the iterator directly to the application: 1 provides a unified iterative Method 2 lazy computation that does not depend on the index, For example, to fetch each line of a fileIv.

, 8, 12]]This in turn writes the same as follows:transposed = []for i in Range (4): transposed_row = [] for row in matrix: transposed_row.append (Row[i]) Transposed.append (transposed_row) Print transposed# [[1, 5, 9], [2, 6, 10], [3, 7, 11], [4, 8, 12]]There is also a python built-in function zip (), also can be implemented as above functionZip (*matrix) # [(1, 5, 9), (2, 6, 10), (3, 7, 11), (4, 8, 12)]2.del statement (The DEL statement)>>> a = [-1, 1, 66.25, 333, 333, 1234.5]>>

exactly the same:>>> for N in Fab (5): ... Print N ... 1 1 2) 3 5　　Simply put, the function of yield is to turn a function into a generator, the function with yield is no longer a normal function, the Python interpreter treats it as a generator, and the Call to FAB (5) does not execute the FAB function, but instead returns a Iterab Le Object! When the For loop executes, each loop executes the code

Generator Iterators Built-in functions Homework First, generator1.1. List GeneratorProblem Introduction: See List [0, 1, 2, 3, 4, 5, 6, 7, 8, 9], I ask you to add 1 to each value in the tableProgramme one:A = [1,3,4,6,7,7,8,9,11]for index,i in Enumerate (a): A[index] +=1print (a) original value modifiedScenario Two:>>> a[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]>>> a = map (lambda x:x+1, a) >>> AScenario Three: List Builder>>> a = [i+1 for i

The generator is a very cool feature in python.2.2 becomes a part of the standard. In many cases, it allows you to simplify operations related to unbounded (infinite) sequences in an elegant and lower memory consumption mode. A generator is a special function that can be used as an iterator. Its function implementation relies on the keyword yield. The following is a simple demonstration of how it operates:>

　　Introduced1, generator expressions (generator expression) are also called generator derivation or generator parsing, and the usage is very similar to the list derivation, in the form generator deduction using parentheses (parentheses) as the delimiter, Instead of the squar

In understanding the data structure of Python, the container (container), the Iteration object (iterable), the iterator (iterator), the generator (generator), the list/collection/dictionary derivation (list,set,dict Comprehension) Many concepts are mixed together, it is inevitable for beginners to confused, I will use an article to try to put these concepts and their relationship between the clear.Container

= "Nicholas Zhao Si" print ("Hip-hop dance" if name == "Nicholas Zhao Si" else "Can't hip-hop dance") One yuan: "Hip-hop dance" Binary: Judgment by if statement Ternary: "No hip-hop dance" Output results: Hip-hop In fact, it is well understood that the if front can be understood as the return result that evaluates to true, else is the return result that evaluates to False, this is the ternary operation. Ternary operations can also be used in conjunction with list generation,

Based on the revision and source code analysis of mybatis-generator-core 1.3.5, mybatisgeneratorcoreProject Description Mybatis-generator is used to generate code files such as entity classes based on database tables and fields. During the National Day, I analyzed the mybatis-generator-core source code and wrote quite detailed Chinese comments. Let's take a look.

first, the new test projectCreate a new MAVEN project MybatisDemo2, modify Pom.xml to introduce dependencies. Dependencies added on the previous sectionDependency> groupId>Org.mybatis.generatorgroupId> Artifactid>Mybatis-generator-coreArtifactid> version>1.3.2version>Dependency>Build Add PluginBuild> Plugins> plugin> groupId>Org.mybatis.generatorgroupId> Artifactid>Mybatis-