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What is the difference between Non-Repeatable Read and Phantom Read?
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and
A phantom read occurs when, in the course of a transaction, two identical queries are executed, and the collection of rows returned by the second query is different from the first.
Simple examples:
User A runs the same query twice.
In between, User B runs a transaction and commits.
N...
What is the proper way to check if a string is empty in Perl?
...hink that length is the closest test that we have to the expression of the idea that there is nothing in the string.
– brian d foy
Jan 12 '10 at 11:23
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deleting rows in numpy array
... answered Jul 26 '12 at 5:48
Jaidev DeshpandeJaidev Deshpande
2,41611 gold badge1313 silver badges1717 bronze badges
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How to create a temporary directory and get the path / file name in Python
... shutil.rmtree(temp_dir.name) is not necessary.
– sidcha
Nov 14 '19 at 7:14
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How to find the installed pandas version
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In [77]: pd.__version__
Out[77]: '0.12.0-933-g281dc4e'
Pandas also provides a utility function, pd.show_versions(), which reports the version of its dependencies as well:
In [53]: pd.show_versions(as_json=False)
INSTALLED VERSIONS
------------------
commit: None
python: 2.7.6.final.0
python-bi...
Read a zipped file as a pandas DataFrame
...ect, rather than read:
In [11]: crime2013 = pd.read_csv(z.open('crime_incidents_2013_CSV.csv'))
In [12]: crime2013
Out[12]:
<class 'pandas.core.frame.DataFrame'>
Int64Index: 24567 entries, 0 to 24566
Data columns (total 15 columns):
CCN 24567 non-null values
REPO...
What does the “@” symbol do in Powershell?
...to check out Jeffrey Snover's answer below... @ is more than just an array identifier.
– Eric Schoonover
Sep 15 '09 at 6:47
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Using IoC for Unit Testing
...esting because unit testing is all about separating responsibilities.
Consider a class that uses Constructor Injection
public MyClass(IMyDependency dep) { }
In your entire application, it may be that there's a huge dependency graph hidden behind IMyDependency, but in a unit test, you flatten it ...
Can Visual Studio 2012 be installed side-by-side w/ Visual Studio 2010?
...Studio 2012 interfere/break .NET 4 and/or Visual Studio 2010 if installed side-by-side on the same instance of Windows?
15 ...
How to destroy an object?
...t documented on one of the comments from the PHP official manual).
That said, do keep in mind that PHP always destroys the objects as soon as the page is served. So this should only be needed on really long loops and/or heavy intensive pages.
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