大约有 6,900 项符合查询结果（耗时：0.0171秒） [XML]
Delete last char of string
...for example http://blogs.msdn.com/b/ericlippert/archive/2009/05/18/foreach-vs-foreach.aspx)
Using some LINQ:
string strgroupids = groupIds.Aggregate(string.Empty, (p, q) => p + q + ',');
strgroupids = strgroupids.Substring(0, str1.Length - 1);
Without end-substringing:
string strgroupids = g...
Difference between e.target and e.currentTarget
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Here is a good example: joequery.me/code/event-target-vs-event-currenttarget-30-seconds
– Glenn Wark
Mar 1 '17 at 15:51
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What is a “cache-friendly” code?
... people in the field sometimes forget is column-major (ex. fortran,matlab) vs. row-major ordering (ex. c,c++) for storing two dimensional arrays. For example, consider the following matrix:
1 2
3 4
In row-major ordering, this is stored in memory as 1 2 3 4; in column-major ordering, this would be s...
How to create a directory in Java?
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mkdir vs mkdirs
If you want to create a single directory use mkdir
new File("/path/directory").mkdir();
If you want to create a hierarchy of folder structure use mkdirs
new File("/path/directory").mkdirs();
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Parsing HTML using Python
...ml is extremely fast:
http://blog.dispatched.ch/2010/08/16/beautifulsoup-vs-lxml-performance/
http://www.ianbicking.org/blog/2008/03/python-html-parser-performance.html
And with cssselect it’s quite easy to use for scraping HTML pages too:
from lxml.html import parse
doc = parse('http://www.g...
Throw away local commits in Git
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@TarunKumar THANK YOU! I am using VS integration, and your solution was the only way I was able to wipe out a bunch of merge commits that I didn't want in a branch I didn't have permission to check in.
– DVK
Nov 13 '18 a...
Combining two Series into a DataFrame in pandas
...at you should prefer doing the concat once pd.concat([list_of_dataframes]) vs concating many times new_df = pd.DataFrame(); for df in list_of_dsf: new_df = pd.concat([new_df, df]) or similar.
– Andy Hayden
Oct 14 '15 at 22:07
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Perforce for Git users? [closed]
... full power of Perforce workspaces read Configuring P4.
Explicit Checkout vs. Implicit Checkout
One of the biggest challenges for users moving from Git to Perforce is the concept of explicit checkout. If you are accustomed to the Git/SVN/CVS workflow of changing files and then telling the version ...
How to determine the screen width in terms of dp or dip at runtime in Android?
...tant difference between using Configuration's screenWidthDp/screenHeightDp vs DisplayMetrics widthPixels/heightPixels is Configuration returns the usable display dimensions (minus the status bar etc), while DisplayMetrics returns the full screen dimensions.
– Nick Baicoianu
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Selecting/excluding sets of columns in pandas [duplicate]
... It seems that the drop method is slightly faster (~515 µs vs ~680 µs), at least in some tests on a 15611 rows x 5 columns dataframe of which I wanted to drop 3 columns, in python 3.6 and pandas 0.20.3.
– bli
Nov 8 '17 at 17:12
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