This question already has an answer here: Understanding Python's slice notation 29 answers It slices the string to omit the last character, in this case a newline character: >>> 'testn'[:-1] 'test' Since this works even on empty strings, it's a pretty safe way of removing that last character, if present: >>> ''[:-1] '' This works on any sequence, not just strings
这个问题在这里已经有了答案： 了解Python的切片符号29个答案 它切割字符串以省略最后一个字符，在这种情况下为换行符： >>> 'testn'[:-1] 'test' 既然这可以在空字符串上工作，如果存在的话，这是删除最后一个字符的一种非常安全的方式： >>> ''[:-1] '' 这适用于任何序列，而不仅仅是字符串。 它意味着“序列的所有元素，但最后”。 在f.readline()[:-1]的上下文中，它意味着“我非常确定该行以换行
Possible Duplicate: Explain slice notation I'm trying to understand the following piece of code: # node list n = [] for i in xrange(1, numnodes + 1): tmp = session.newobject(); n.append(tmp) link(n[0], n[-1]) Specifically, I don't understand what the index -1 refers to. If the index 0 refers to the first element, then what does -1 refer to? Negative numbers mean that you
可能重复： 解释切片符号 我试图理解下面的一段代码： # node list n = [] for i in xrange(1, numnodes + 1): tmp = session.newobject(); n.append(tmp) link(n[0], n[-1]) 具体来说，我不明白索引-1是指什么。 如果索引0引用第一个元素，那么-1是指什么？ 负数表示你从右而不是左数起。 所以， list[-1]指向最后一个元素， list[-2]是倒数第二个，依此类推。 列表索引-x表示列表末尾的第x个项目，因此n[-
This question already has an answer here: Understanding Python's slice notation 29 answers : is the delimiter of the slice syntax to 'slice out' sub-parts in sequences , [start:end] [1:5] is equivalent to "from 1 to 5" (5 not included) [1:] is equivalent to "1 to end" [len(a):] is equivalent to "from length of a to end" Watch https://youtu.be/tKTZoB2Vjuk?t=41m40s at around 40:00
这个问题在这里已经有了答案： 了解Python的切片符号29个答案 :是片段语法的分隔符，用于按顺序“分出”子部分， [start:end] [1:5] is equivalent to "from 1 to 5" (5 not included) [1:] is equivalent to "1 to end" [len(a):] is equivalent to "from length of a to end" 在40:00左右观看https://youtu.be/tKTZoB2Vjuk?t=41m40s，他开始解释这一点。 也适用于元组，词典和列表。 切片操作员。 http://docs.python
This question already has an answer here: Understanding Python's slice notation 29 answers Simple: st = "abcdefghij" st = st[:-1] there is also another way that show how it is done with steps: list1 = "abcdefghij" list2 = list(list1) print (list2) list3 = list2[:-1] print (list3) This is also a way with the user inputting a word: list1 = input ("Enter :") list2 = list(list1) print (
这个问题在这里已经有了答案： 了解Python的切片符号29个答案 简单： st = "abcdefghij" st = st[:-1] 还有另一种方式可以说明它是如何完成的： list1 = "abcdefghij" list2 = list(list1) print (list2) list3 = list2[:-1] print (list3) 这也是用户输入单词的一种方式： list1 = input ("Enter :") list2 = list(list1) print (list2) list3 = list2[:-1] print (list3) 为了让它拿走列表中的最后一个单词： list1
I'm using Word 2013 to automatically create a report as a docx and then save it as a pdf format. But when I call the function SaveAs2(), the script pop out the "save as" windows and throws this exception : (-2147352567, 'Exception occurred.', (0, u'Microsoft Word', u'Command failed', u'wdmain11.chm', 36966, -2146824090), None) Here is my code to open and to save as a new file:
我使用的Word 2013自动创建一个报告为docx，然后将其保存为PDF格式。 但是，当我调用SaveAs2（）函数时，脚本弹出“另存为”窗口并引发此异常： (-2147352567, 'Exception occurred.', (0, u'Microsoft Word', u'Command failed', u'wdmain11.chm', 36966, -2146824090), None) 这是我的代码打开并保存为一个新文件： self.path = os.path.abspath(path) self.wordApp = win32.Dispatch('Word.Application') #create a word
I want to copy a 2D list, so that if I modify one list, the other is not modified. For a one-dimensional list, I just do this: a = [1, 2] b = a[:] And now if I modify b , a is not modified. But this doesn't work for a two-dimensional list: a = [[1, 2],[3, 4]] b = a[:] If I modify b , a gets modified as well. How do I fix this? 对于一个更通用的解决方案，无论维数如何，都可以使用copy.
我想复制一个2D列表，这样如果我修改一个列表，另一个不会被修改。 对于一维列表，我只是这样做的： a = [1, 2] b = a[:] 而现在如果我修改b ，则a不会被修改。 但是这不适用于二维列表： a = [[1, 2],[3, 4]] b = a[:] 如果我修改b ， a也会被修改。 我该如何解决？ 对于一个更通用的解决方案，无论维数如何，都可以使用copy.deepcopy() ： import copy b = copy.deepcopy(a) b = [x[:] for x in a]
I am developing validation and linting utility to be integrated with various commit hooks, including Git one https://github.com/miohtama/vvv Currently validators and linters are run against the whole project codebase on every commit. However, it would be much more optimal to run them against changed files only. For this, I would need to know changed files list in my Git precommit hook (in P
我正在开发验证和linting实用程序，以便与各种提交钩子（包括Git）集成 https://github.com/miohtama/vvv 目前验证器和短语在每次提交时都针对整个项目代码库运行。 但是，仅仅针对更改的文件运行它们会更加优化。 为此，我需要知道Git precommit钩子中的文件列表（使用Python） https://github.com/miohtama/vvv/blob/master/vvv/hooks/git.py 我必须提供哪些选项才能提取已更改的文件列表（如果存在的话，请在Python
I know the obvious answer is to use virtualenv and virtualenvwrapper, but for various reasons I can't/don't want to do that. So how do I modify the command pip install package_name to make pip install the package somewhere other than the default site-packages ? Use: pip install --install-option="--prefix=$PREFIX_PATH" package_name You might also want to use --ignore-installed to f
我知道明显的答案是使用virtualenv和virtualenvwrapper，但由于各种原因，我不能/不想这样做。 那么我该如何修改这个命令 pip install package_name 使pip安装在默认site-packages以外的地方？ 使用： pip install --install-option="--prefix=$PREFIX_PATH" package_name 您可能还想使用--ignore-installed来强制使用此新前缀重新安装所有依赖项。 您可以多次使用--install-option来添加可用于python setup.py install
It looks strange, that the pip documentation (here: https://pip.pypa.io/en/stable/installing/) tells "To install pip, securely download get-pip.py", but there is no checksum to check if I downloaded the good get-pip.py file. It's recommended to use package manager like apt or yum , but what can I do on Mac? So the question is where can I obtain checksum of get-pip.py to download
看起来奇怪的是， pip文档（这里是：https：//pip.pypa.io/en/stable/installing/）告诉“安装pip， 安全地下载get-pip.py”，但是没有校验和来检查如果我下载了好的get-pip.py文件。 建议使用apt或yum等软件包管理器，但是我可以在Mac上执行哪些操作？ 所以问题是我可以从哪里获得get-pip.py校验和以便通过wget下载它，检查它是否正常（检查它是否完整，文件在传输过程中是否损坏或修改）并将其安装到我的Mac ？ 您可以直接从
I have a Mac running Python 2.6. When I try to use easy_install I get this message: /usr/bin/easy_install-2.6:7: UserWarning: Module pkg_resources was already imported from /System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python/pkg_resources.pyc, but /Library/Python/2.6/site-packages is being added to sys.path from pkg_resources import load_entry_point /usr/bin/easy_instal
我有一台运行Python 2.6的Mac。 当我尝试使用easy_install我收到以下消息： /usr/bin/easy_install-2.6:7: UserWarning: Module pkg_resources was already imported from /System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python/pkg_resources.pyc, but /Library/Python/2.6/site-packages is being added to sys.path from pkg_resources import load_entry_point /usr/bin/easy_install-2.6:7: User