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MySQL, Check if a column exists in a table with SQL
...pecific column, and if not — create it. Otherwise do nothing. This is really an easy procedure in any enterprise-class database, yet MySQL seems to be an exception.
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How do I list the symbols in a .so file
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Note that readelf -Ws will show you all symbols, and nm -g shows only the externally visible symbols. This may be confusing if you are examining multiple symbol files and start interchanging your commands.
– Andrew B
May 2...
Python nested functions variable scoping [duplicate]
I've read almost all the other questions about the topic, but my code still doesn't work.
10 Answers
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How to plot two columns of a pandas data frame using points?
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You can specify the style of the plotted line when calling df.plot:
df.plot(x='col_name_1', y='col_name_2', style='o')
The style argument can also be a dict or list, e.g.:
import numpy as np
import pandas as pd
d = {'one' : np.random.rand(10),
'two' : np.random.rand(...
Convert string to Python class object?
... there's a class with that name in the currently defined namespace. Essentially, I want the implementation for a function which will produce this kind of result:
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Extract file name from path, no matter what the os/path format
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Using os.path.split or os.path.basename as others suggest won't work in all cases: if you're running the script on Linux and attempt to process a classic windows-style path, it will fail.
Windows paths can use either backslash or forward slash as path separator. Therefore, the ntpath module (whi...
How to [recursively] Zip a directory in PHP?
...ce), file_get_contents($source));
}
return $zip->close();
}
Call it like this:
Zip('/folder/to/compress/', './compressed.zip');
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UITableViewCell, show delete button on swipe
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During startup in (-viewDidLoad or in storyboard) do:
self.tableView.allowsMultipleSelectionDuringEditing = NO;
Override to support conditional editing of the table view. This only needs to be implemented if you are going to be returning NO for some items. By default, all items are editable....
The model used to open the store is incompatible with the one used to create the store
...el select your new version of data model for current data model
THAT'S NOT ALL ) You should perform so called "light migration".
Go to your AppDelegate and find where the persistentStoreCoordinator is being created
Find this line if (![_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteS...
Find an item in List by LINQ?
Here I have a simple example to find an item in a list of strings. Normally I use for loop or anonymous delegate to do it like this:
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