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How to drop rows of Pandas DataFrame whose value in a certain column is NaN
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@wes-mckinney could please let me know if dropna () is a better choice over pandas.notnull in this case ? If so, then why ?
– stormfield
Sep 7 '17 at 11:53
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How exactly does the python any() function work?
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If you use any(lst) you see that lst is the iterable, which is a list of some items. If it contained [0, False, '', 0.0, [], {}, None] (which all have boolean values of False) then any(lst) would be False. If lst also contain...
Array.Copy vs Buffer.BlockCopy
...time when you are copying primitive type arrays, or should you only use it if you're coding for performance? Is there anything inherently dangerous about using Buffer.BlockCopy over Array.Copy ?
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Retrieve only static fields declared in Java class
...s = new ArrayList<Field>();
for (Field field : declaredFields) {
if (java.lang.reflect.Modifier.isStatic(field.getModifiers())) {
staticFields.add(field);
}
}
share
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improve ...
SQL JOIN - WHERE clause vs. ON clause
...oins .
The answer may be related (or even the same) but the question is different.
18 Answers
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Suppress/ print without b' prefix for bytes in Python 3
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If the bytes use an appropriate character encoding already; you could print them directly:
sys.stdout.buffer.write(data)
or
nwritten = os.write(sys.stdout.fileno(), data) # NOTE: it may write less than len(data) bytes
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Android onCreate or onStartCommand for starting service
...alled once per instantiated object.
You only need to implement onCreate() if you actually want/need to initialize something only once.
onStartCommand() is called every time a client starts the service using startService(Intent intent). This means that onStartCommand() can get called multiple times...
find -exec cmd {} + vs | xargs
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Speed difference will be insignificant.
But you have to make sure that:
Your script will not assume that no
file will have space, tab, etc in
file name; the first version is
safe, the second is not.
Your script will not treat a f...
Increment a database field by 1
With MySQL, if I have a field, of say logins, how would I go about updating that field by 1 within a sql command?
5 Answers...
How to check whether a Storage item is set?
How can I check if an item is set in localStorage ? Currently I am using
13 Answers
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