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Convert columns to string in Pandas
...e looking for the to_json function, which will convert keys to valid json (and therefore your keys to strings):
In [11]: df = pd.DataFrame([['A', 2], ['A', 4], ['B', 6]])
In [12]: df.to_json()
Out[12]: '{"0":{"0":"A","1":"A","2":"B"},"1":{"0":2,"1":4,"2":6}}'
In [13]: df[0].to_json()
Out[13]: '{"...
Can not connect to local PostgreSQL
...really looks like a file permissions error. Unix domain sockets are files and have user permissions just like any other. It looks as though the OSX user attempting to access the database does not have file permissions to access the socket file. To confirm this I've done some tests on Ubuntu and p...
Open file dialog and select a file using WPF controls and C#
I have a TextBox named textbox1 and a Button named button1 .
When I click on button1 I want to browse my files to search only for image files (type jpg, png, bmp...).
And when I select an image file and click Ok in the file dialog I want the file directory to be written in the textbox1.tex...
Nesting await in Parallel.ForEach
...The whole idea behind Parallel.ForEach() is that you have a set of threads and each thread processes part of the collection. As you noticed, this doesn't work with async-await, where you want to release the thread for the duration of the async call.
You could “fix” that by blocking the ForE...
How can I find the length of a number?
...34567;
x.toString().length;
This process will also work forFloat Number and for Exponential number also.
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How to serialize SqlAlchemy result to JSON?
... {}
for field in [x for x in dir(obj) if not x.startswith('_') and x != 'metadata']:
data = obj.__getattribute__(field)
try:
json.dumps(data) # this will fail on non-encodable values, like other classes
fields[field]...
What's wrong with nullable columns in composite primary keys?
...keys is not clean relational database design.
If there are two entities A and B where A can optionally be related to B, the clean solution is to create a resolution table (let's say AB). That table would link A with B: If there is a relationship then it would contain a record, if there isn't then i...
Migrating from JSF 1.2 to JSF 2.0
...SF 1.2 to 2.0 depends on the view technology which you are currently using and which you want to use.
JSP 2.x to JSP 2.x = Almost no effort.
Facelets 1.x to Facelets 2.0 = Little effort.
JSP 2.x to Facelets 2.0 = Lot of effort. Double this if you also have custom components.
Basic changes
Reg...
How to re-create database for Entity Framework?
... losing data, I just want to be able to start fresh, recreate the database and start using Code-First migrations.
7 Answer...
Using IQueryable with Linq
...ing data from a table in two ways, one which returns IEnumerable<T>, and one which returns an IQueryable<T>. Say, for example, you have a Products table, and you want to get all of the products whose cost is >$25.
If you do:
IEnumerable<Product> products = myORM.GetProducts(...