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Pip freeze vs. pip list
...you are using a virtualenv, you can specify a requirements.txt file to install all the dependencies.
A typical usage:
$ pip install -r requirements.txt
The packages need to be in a specific format for pip to understand, which is
feedparser==5.1.3
wsgiref==0.1.2
django==1.4.2
...
That is the ...
Scala list concatenation, ::: vs ++
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UnicodeDecodeError when reading CSV file in Pandas with Python
...= "ISO-8859-1"), or alternatively encoding = "utf-8" for reading, and generally utf-8 for to_csv.
You can also use one of several alias options like 'latin' instead of 'ISO-8859-1' (see python docs, also for numerous other encodings you may encounter).
See relevant Pandas documentation,
python doc...
What are the main performance differences between varchar and nvarchar SQL Server data types?
I'm working on a database for a small web app at my school using SQL Server 2005 .
I see a couple of schools of thought on the issue of varchar vs nvarchar :
...
ActiveRecord: size vs count
...l valid.
You'll adapt the function you use depending on your needs.
Basically:
if you already load all entries, say User.all, then you should use length to avoid another db query
if you haven't anything loaded, use count to make a count query on your db
if you don't want to bother with these con...
Unable to find specific subclass of NSManagedObject
...://stackoverflow.com/a/31287260/1187415).
Remark: This answer was originally written for Xcode 6.
There were some changes in the various Xcode 7 beta releases with
respect to this problem. Since it is an accepted answer with many
upvotes and links to it, I have tried to summarize the situation
fo...
subtle differences between JavaScript and Lua [closed]
...= operators are of lower precedence than >, >=, <, <=. In Lua, all comparison operators are the same precedence.
Lua supports tail calls.
UPDATE: JS now supports tail calls.
Lua supports assignment to a list of variables. While it isn't yet standard in Javascript, Mozilla's JS engine ...
Is std::unique_ptr required to know the full definition of T?
...s. However shared_ptr and unique_ptr are partial exceptions. Some, but not all of their members can be instantiated with incomplete types. The motivation for this is to support idioms such as pimpl using smart pointers, and without risking undefined behavior.
Undefined behavior can occur when you h...
Difference between __str__ and __repr__?
...e come right out and say it — I do not believe in debuggers. I don’t really know how to use any debugger, and have never used one seriously. Furthermore, I believe that the big fault in debuggers is their basic nature — most failures I debug happened a long long time ago, in a galaxy far far a...
How to import multiple .csv files at once?
...ariables but each from different times.
Is there a way in R to import them all simultaneously rather than having to import them all individually?
...