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Add a default value to a column through a migration
...to was added in Rails 5+ in this commit: github.com/rails/rails/pull/20018/files
– Joshua Pinter
Dec 29 '18 at 19:03
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Installing specific package versions with pip
... MySQL_python
pip install -Iv http://sourceforge.net/projects/mysql-python/files/mysql-python/1.2.2/MySQL-python-1.2.2.tar.gz/download
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Replacing blank values (white space) with NaN in pandas
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If you are exporting the data from the CSV file it can be as simple as this :
df = pd.read_csv(file_csv, na_values=' ')
This will create the data frame as well as replace blank values as Na
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How does TestFlight do it?
...y install it on any device. For an enterprise distribution provisioning profile you don't have to specify the devices and you can (at least technically) install the binary on any device. However, the license restricts you to only install it within the company that the distribution profile was issued...
How to create the most compact mapping n → isprime(n) up to a limit N?
... the internet with N stretching up to at least fifty million. Download the files and use them, it's likely to be much faster than any other method you'll come up with.
If you want an actual algorithm for making your own primes, Wikipedia has all sorts of good stuff on primes here, including links t...
How and/or why is merging in Git better than in SVN?
...esets or store any tracking information -- it just stores the state of the files at each commit and uses heuristics to locate renames and code movements as required (the on-disk storage is more complicated than this, but the interface it presents to the logic layer exposes no tracking).
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A Java API to generate Java source files [closed]
I'm looking for a framework to generate Java source files.
15 Answers
15
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Objective-C pass block as parameter
...d functions to perform anything in background and on main queue.
blocks.h file
void performInBackground(void(^block)(void));
void performOnMainQueue(void(^block)(void));
blocks.m file
#import "blocks.h"
void performInBackground(void(^block)(void)) {
if (nil == block) {
return;
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How do you embed binary data in XML?
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Wow. This will make the average kilobyte-range file about 230 times larger :)
– Nyerguds
Aug 8 '11 at 12:03
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Error: “dictionary update sequence element #0 has length 1; 2 is required” on Django 1.4
...t;>> a_dictionary.update([[1]])
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ValueError: dictionary update sequence element #0 has length 1; 2 is required
It's hard to tell where is the cause in your code unless you show your code, full traceback.
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