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Iterating over dictionaries using 'for' loops
... the case in Python3.6, but note that it's not guaranteed behaviour yet)
>>> d = {'x': 1, 'y': 2, 'z': 3}
>>> list(d)
['y', 'x', 'z']
>>> d.keys()
['y', 'x', 'z']
For your example, it is a better idea to use dict.items():
>>> d.items()
[('y', 2), ('x', 1), ('...
Finding duplicate values in a SQL table
...il, COUNT(*)
FROM
users
GROUP BY
name, email
HAVING
COUNT(*) > 1
Simply group on both of the columns.
Note: the older ANSI standard is to have all non-aggregated columns in the GROUP BY but this has changed with the idea of "functional dependency":
In relational database theor...
Visual Studio hot keys change occasionally, specifically F6 vs Ctrl-Shift-B for building. WHY?
... hotkeys settings, you just follow the solution proposed by others (Tools > Options > Environment > Keyboard > Visual C# 2015). BUT this will only change the keyboard settings to C# settings while keeping rest of the settings as General settings only.
If you are really intending to chan...
Using Git with an existing Xcode project
...art below.)
But it you are working with an existing project, go to Xcode > Preferences... > Source Control and check the Enable Source Control box.
Then in the main Source Control menu choose Create Working Copy....
(If you get a "Please tell me who you are" error the see this question/answ...
How to add a custom loglevel to Python's logging facility
...le or if the method name is already present
Example
-------
>>> addLoggingLevel('TRACE', logging.DEBUG - 5)
>>> logging.getLogger(__name__).setLevel("TRACE")
>>> logging.getLogger(__name__).trace('that worked')
>>> logging.trace('so did t...
Visual Studio: ContextSwitchDeadlock
...ur code has an issue, just that there is a potential. If you go to Debug > Exceptions in the menu and expand the Managed Debugging Assistants, you will find ContextSwitchDeadlock is enabled. If you disable this, VS will no longer warn you when items are taking a long time to process. In some c...
Get column index from column name in python pandas
... column location (the other way around to the OP question), you can use:
>>> df.columns.get_values()[location]
Using @DSM Example:
>>> df = DataFrame({"pear": [1,2,3], "apple": [2,3,4], "orange": [3,4,5]})
>>> df.columns
Index(['apple', 'orange', 'pear'], dtype='obje...
MySQL - Using COUNT(*) in the WHERE clause
...
try this;
select gid
from `gd`
group by gid
having count(*) > 10
order by lastupdated desc
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Cannot find or open the PDB file in Visual Studio C++ 2010
...hese are system DLLs, which you don't have debug symbols for. Go to Tools->Options->Debugging->Symbols and select checkbox "Microsoft Symbol Servers", Visual Studio will download PDBs automatically. Or you may just ignore these warnings if you don't need to see correct call stack in these m...
python numpy ValueError: operands could not be broadcast together with shapes
...alars from matrix y onto X then you need to perform X * y.T.
Example:
>>> import numpy as np
>>>
>>> X = np.arange(8).reshape(4, 2)
>>> y = np.arange(2).reshape(1, 2) # create a 1x2 matrix
>>> X * y
array([[0,1],
[0,3],
[0,5],
[0...