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How does one reorder columns in a data frame?
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Your dataframe has four columns like so df[,c(1,2,3,4)].
Note the first comma means keep all the rows, and the 1,2,3,4 refers to the columns.
To change the order as in the above question do df2[,c(1,3,2,4)]
If you want to output this file as a csv, do write.csv(df2, file="somedf.csv")
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File Upload using AngularJS
...orm file uploading. These two have explicit support for older browsers:
https://github.com/leon/angular-upload - uses iframes as a fallback
https://github.com/danialfarid/ng-file-upload - uses FileAPI/Flash as a fallback
And some other options:
https://github.com/nervgh/angular-file-upload/
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ssl证书申请报错：challenge = [c for c in authorization[\'challenges\']...
...错：challenge = [c for c in authorization['challenges'] if c['type'] == "http-01"][0] IndexError: list index out of rangechallenge-list-index-out-of-range使用acme-tiny申请ssl证书时报错：challenge = [c for c in authorization[& 39;challenges& 39;] if c[& 39;type& 39;] == "http-01"][0] Inde...
Defeating a Poker Bot
...e, which you reference in your question, has absolutely nothing to do with HTTP. In fact, I doubt there are any gambling poker sites that use HTTP. Your question, answer, and comments reveal that you know very little about this subject. You should try knowing what you're talking about before giving ...
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Adding one day to a date
My code to add one day to a date returns a date before day adding:
2009-09-30 20:24:00 date after adding one day SHOULD be rolled over to the next month: 1970-01-01 17:33:29
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TCP 的那些事儿（下） - 更多技术 - 清泛网 - 专注C/C++及内核技术
...可能出现DDoS攻击，Zero Window也不例外，一些攻击者会在和HTTP建好链发完GET请求后，就把Window设置为0，然后服务端就只能等待进行ZWP，于是攻击者会并发大量的这样的请求，把服务器端的资源耗尽。（关于这方面的攻击，大家可...
Split column at delimiter in data frame [duplicate]
I would like to split one column into two within at data frame based on a delimiter. For example,
6 Answers
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How do I get a substring of a string in Python?
Is there a way to substring a string in Python, to get a new string from the third character to the end of the string?
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Set the value of a variable with the result of a command in a Windows batch file
...in a Bash environment, to set the value of a variable as the result of a command, I usually do:
5 Answers
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