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Skip rows during csv import pandas
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^ No need to import at all, it is directly accessible as pd.compat.StringIO .
– cs95
Apr 8 '19 at 17:51
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Do declared properties require a corresponding instance variable?
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In your interface, you can formally declare an instance variable between the braces, or via @property outside the braces, or both. Either way, they become attributes of the class. The difference is that if you declare @property, then you can implement usin...
Difference between “module.exports” and “exports” in the CommonJs Module System
...ns to be set to module.exports.
At the end of your file, node.js will basically 'return' module.exports to the require function. A simplified way to view a JS file in Node could be this:
var module = { exports: {} };
var exports = module.exports;
// your code
return module.exports;
If you set a...
Deleting rows with MySQL LEFT JOIN
...ed May 4 '10 at 6:26
Daniel VassalloDaniel Vassallo
301k6666 gold badges475475 silver badges424424 bronze badges
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How do I setup a SSL certificate for an express.js server?
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Other options for createServer are at: http://nodejs.org/api/tls.html#tls_tls_createserver_options_secureconnectionlistener
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Difference between Django's annotate and aggregate methods?
...rage_price': 34.35}
Returns a dictionary containing the average price of all books in the queryset.
Annotation
>>> q = Book.objects.annotate(num_authors=Count('authors'))
>>> q[0].num_authors
2
>>> q[1].num_authors
1
q is the queryset of books, but each book has been...
Access nested dictionary items via a list of keys?
...ist, value):
getFromDict(dataDict, mapList[:-1])[mapList[-1]] = value
All but the last element in mapList is needed to find the 'parent' dictionary to add the value to, then use the last element to set the value to the right key.
Demo:
>>> getFromDict(dataDict, ["a", "r"])
1
>>&g...
Combining INSERT INTO and WITH/CTE
...ions go at the top.
Wrapping every insert in a CTE has the benefit of visually segregating the query logic from the column mapping.
Spot the mistake:
WITH _INSERT_ AS (
SELECT
[BatchID] = blah
,[APartyNo] = blahblah
,[SourceRowID] = blahblahblah
FROM Table1 AS t1
)
INSERT ...
How can I use if/else in a dictionary comprehension?
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@Marcin's answer covers it all, but just in case someone wants to see an actual example, I add two below:
Let's say you have the following dictionary of sets
d = {'key1': {'a', 'b', 'c'}, 'key2': {'foo', 'bar'}, 'key3': {'so', 'sad'}}
and you want ...
Check if OneToOneField is None in Django
... Thank you for this solution. Unfortunately, this doesn't work all the time. In case you want to work with select_related() now or in the future -- or maybe even to be sure you also handle other sorts of magic which may happen elsewhere -- you have to extend the test as follows: if hasat...