with-statement

Count the number of rows in another sheet

由 最后都变了- 提交于 2019-11-26 04:28:34
问题 I have looked at the suggested questions to find the answer to my problem. The closest question is called: Count number of rows in a different Excel Sheet Count number of rows in a different Excel Sheet The solution to that problem does not work for me. I am trying to count the number of rows in a range in a different worksheet than the active worksheet. Here is my code: Sub verbflashcards() Dim wordcount As Long With Worksheets(\"Verbs\") wordcount = .Range(Cells(4, 1), Cells(4, 1).End

Multiple variables in a 'with' statement?

由 百般思念 提交于 2019-11-26 04:06:43
问题 Is it possible to declare more than one variable using a with statement in Python? Something like: from __future__ import with_statement with open(\"out.txt\",\"wt\"), open(\"in.txt\") as file_out, file_in: for line in file_in: file_out.write(line) ... or is cleaning up two resources at the same time the problem? 回答1: It is possible in Python 3 since v3.1 and Python 2.7. The new with syntax supports multiple context managers: with A() as a, B() as b, C() as c: doSomething(a,b,c) Unlike the

Create a “with” block on several context managers? [duplicate]

由 丶灬走出姿态 提交于 2019-11-26 03:56:11
This question already has an answer here: Multiple variables in a 'with' statement? 5 answers Suppose you have three objects you acquire via context manager, for instance A lock, a db connection and an ip socket. You can acquire them by: with lock: with db_con: with socket: #do stuff But is there a way to do it in one block? something like with lock,db_con,socket: #do stuff Furthermore, is it possible, given an array of unknown length of objects that have context managers, is it possible to somehow do: a=[lock1, lock2, lock3, db_con1, socket, db_con2] with a as res: #now all objects in array

Explaining Python's '__enter__' and '__exit__'

由 那年仲夏 提交于 2019-11-26 02:26:51
问题 I saw this in someone\'s code. What does it mean? def __enter__(self): return self def __exit__(self, type, value, tb): self.stream.close() from __future__ import with_statement#for python2.5 class a(object): def __enter__(self): print \'sss\' return \'sss111\' def __exit__(self ,type, value, traceback): print \'ok\' return False with a() as s: print s print s 回答1: Using these magic methods ( __enter__ , __exit__ ) allows you to implement objects which can be used easily with the with

Create a “with” block on several context managers? [duplicate]

由 最后都变了- 提交于 2019-11-26 01:14:27
问题 This question already has an answer here: Multiple variables in a 'with' statement? 6 answers Suppose you have three objects you acquire via context manager, for instance A lock, a db connection and an ip socket. You can acquire them by: with lock: with db_con: with socket: #do stuff But is there a way to do it in one block? something like with lock,db_con,socket: #do stuff Furthermore, is it possible, given an array of unknown length of objects that have context managers, is it possible to

What is the python “with” statement designed for?

由 给你一囗甜甜゛ 提交于 2019-11-25 23:57:17
问题 I came across the Python with statement for the first time today. I\'ve been using Python lightly for several months and didn\'t even know of its existence! Given its somewhat obscure status, I thought it would be worth asking: What is the Python with statement designed to be used for? What do you use it for? Are there any gotchas I need to be aware of, or common anti-patterns associated with its use? Any cases where it is better use try..finally than with ? Why isn\'t it used more widely?

Are there legitimate uses for JavaScript's “with” statement?

由 回眸只為那壹抹淺笑 提交于 2019-11-25 23:03:25
问题 Alan Storm\'s comments in response to my answer regarding the with statement got me thinking. I\'ve seldom found a reason to use this particular language feature, and had never given much thought to how it might cause trouble. Now, I\'m curious as to how I might make effective use of with , while avoiding its pitfalls. Where have you found the with statement useful? 回答1: Another use occurred to me today, so I searched the web excitedly and found an existing mention of it: Defining Variables
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