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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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Efficiently test if a port is open on Linux?
...output connection
exec 6<&- # close input connection
To determine if someone is listening, attempt to connect by loopback. If it fails, then the port is closed or we aren't allowed access. Afterwards, close the connection.
Modify this for your use case, such as sending an email, exiting t...
Regular expression to match DNS hostname or IP Address?
...\.
ValidHostnameRegex is valid as per RFC 1123. Originally, RFC 952 specified that hostname segments could not start with a digit.
http://en.wikipedia.org/wiki/Hostname
The original specification of
hostnames in RFC
952,
mandated that labels could not start
with a digit or with a hyp...
Entity Framework Refresh context?
...entities in your context is to dispose your context and create a new one.
If you really need to refresh some entity and you are using Code First approach with DbContext class, you can use
public static void ReloadEntity<TEntity>(
this DbContext context,
TEntity entity)
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How do you specify a different port number in SQL Management Studio?
...Microsoft SQL 2005 server which is not on port 1433. How do I indicate a different port number when connecting to the server using SQL Management Studio?
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In Python, how do I create a string of n characters in one line of code?
...me letter 10 times:
string_val = "x" * 10 # gives you "xxxxxxxxxx"
And if you want something more complex, like n random lowercase letters, it's still only one line of code (not counting the import statements and defining n):
from random import choice
from string import ascii_lowercase
n = 10
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How to save a plot as image on the disk?
...the (combined) help page for the graphical formats ?png, ?bmp, ?jpeg and ?tiff as well as in the separate help page for ?pdf.
Note however that the image might look different on disk to the same plot directly plotted to your screen, for example if you have resized the on-screen window.
Note that...
Get Unix Epoch Time in Swift
How do you get the seconds from epoch in Swift?
5 Answers
5
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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...
Import CSV to SQLite
...v foo
The first command creates the column names for the table. However, if you want the column names inherited from the csv file, you might just ignore the first line.
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