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What is the difference between join and merge in Pandas?
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I always use join on indices:
import pandas as pd
left = pd.DataFrame({'key': ['foo', 'bar'], 'val': [1, 2]}).set_index('key')
right = pd.DataFrame({'key': ['foo', 'bar'], 'val': [4, 5]}).set_index('key')
left.join(right, lsuffix='_l', rsuffix='_r')
val_l ...
How do you test that a Python function throws an exception?
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I'm using Python 2.7.10, and the above doesn't work; context.exception does not give the message; it is a type.
– LateCoder
Feb 25 '16 at 16:55
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Hibernate - Batch update returned unexpected row count from update: 0 actual row count: 0 expected:
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Without code and mappings for your transactions, it'll be next to impossible to investigate the problem.
However, to get a better handle as to what causes the problem, try the following:
In your hibernate configuration, set hibernate.s...
Ignore with CSS?
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With css, you can "hide" the br tags and they won't have an effect:
br {
display: none;
}
If you only want to hide some within a specific heading type, just make your css more specific.
h3 br {
display: none;
}
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PostgreSQL function for last inserted ID
...an id column created with the SERIAL pseudo-type. To avoid relying on this and to feel more clean, you can use instead pg_get_serial_sequence:
INSERT INTO persons (lastname,firstname) VALUES ('Smith', 'John');
SELECT currval(pg_get_serial_sequence('persons','id'));
Caveat: currval() only work...
Create directories using make file
I'm a very new to makefiles and i want to create directories using makefile. My project directory is like this
9 Answers
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How to recognize swipe in all 4 directions
I need to use swipe to recognize swipe gesture down and then right. But on swift UISwipeGestureRecognizer has predeterminate Right direction.. And I don't know how make this for use other directions..
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SetUnhandledExceptionFilter and the C/C++ Runtime Library - C/C++ - 清...
SetUnhandledExceptionFilter and the C/C++ Runtime LibrarySetUnhandledExceptionFilter-and-the-C-C-Runtime-LiThis article presents a fix for SetUnhandledExceptionFilter to work with the CRT.Download source code - 30.9 KBInt...This article presents a fix for SetUnhandledExceptionFilter to work with the...
Hashing a dictionary?
...dictionary is not nested, you could make a frozenset with the dict's items and use hash():
hash(frozenset(my_dict.items()))
This is much less computationally intensive than generating the JSON string or representation of the dictionary.
UPDATE: Please see the comments below, why this approach mi...
Use grep --exclude/--include syntax to not grep through certain files
...Note that the star is escaped with a backslash to prevent it from being expanded by the shell (quoting it, such as --include="*.{cpp,h}", would work just as well). Otherwise, if you had any files in the current working directory that matched the pattern, the command line would expand to something l...