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Initializing a list to a known number of elements in Python [duplicate]
...st thing that comes to mind for me is:
verts = [None]*1000
But do you really need to preinitialize it?
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List all sequences in a Postgres db 8.1 with SQL
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The following query gives names of all sequences.
SELECT c.relname FROM pg_class c WHERE c.relkind = 'S';
Typically a sequence is named as ${table}_id_seq. Simple regex pattern matching will give you the table name.
To get last value of a sequence use the ...
Extracting just Month and Year separately from Pandas Datetime column
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what actually does pd.Datetimeindex do?
– JOHN
Apr 16 '18 at 5:24
1
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How do I add the contents of an iterable to a set?
What is the "one [...] obvious way" to add all items of an iterable to an existing set ?
6 Answers
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Compare two DataFrames and output their differences side-by-side
...original question
The first step is to concatenate the DataFrames horizontally with the concat function and distinguish each frame with the keys parameter:
df_all = pd.concat([df.set_index('id'), df2.set_index('id')],
axis='columns', keys=['First', 'Second'])
df_all
It's pr...
Input and output numpy arrays to h5py
I have a Python code whose output is a sized matrix, whose entries are all of the type float . If I save it with the extension .dat the file size is of the order of 500 MB. I read that using h5py reduces the file size considerably. So, let's say I have the 2D numpy array named A . How do I ...
Iterate keys in a C++ map
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If you really need to hide the value that the "real" iterator returns (for example because you want to use your key-iterator with standard algorithms, so that they operate on the keys instead of the pairs), then take a look at Boost's...
Django Setup Default Logging
...can't seem to figure out how to setup a "default" logger for my Django installation. I would like to use Django 1.3's new LOGGING setting in settings.py .
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How to check if a python module exists without importing it
...ING
When trying to find a submodule, it will import the parent module (for all of the above methods)!
food/
|- __init__.py
|- eggs.py
## __init__.py
print("module food loaded")
## eggs.py
print("module eggs")
were you then to run
>>> import importlib
>>> spam_spec = importli...
UITableViewHeaderFooterView: Unable to change background color
...gn custom view: myTableViewHeaderFooterView.backgroundView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"myImage.png"]];
– skywinder
Jan 16 '14 at 6:28
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