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How to add an empty column to a dataframe?
...t; df = pd.DataFrame({"A": [1,2,3], "B": [2,3,4]})
>>> df
A B
0 1 2
1 2 3
2 3 4
>>> df["C"] = ""
>>> df["D"] = np.nan
>>> df
A B C D
0 1 2 NaN
1 2 3 NaN
2 3 4 NaN
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Convert int to char in java
...ascii value 49 (one corresponding to '1')
If you want to convert a digit (0-9), you can add 48 to it and cast, or something like Character.forDigit(a, 10);.
If you want to convert an int as in ascii value, you can use Character.toChars(48) for example.
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Can't connect to MySQL server error 111 [closed]
I installed mysql server on linux box IP = 192.168.1.100 but when i try to connect to this IP it alway error(111). but use localhost and 127.0.0.1 is OK.
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Python module os.chmod(file, 664) does not change the permission to rw-rw-r— but -w--wx----
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130
Found this on a different forum
If you're wondering why that leading zero is important, it's...
HTML5 record audio to file
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107
There is a fairly complete recording demo available at: http://webaudiodemos.appspot.com/Audio...
SyntaxError: Use of const in strict mode
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How to send only one UDP packet with netcat?
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205
If you are using bash, you might as well write
echo -n "hello" >/dev/udp/localhost/8000
a...
Simple calculations for working with lat/lon and km distance?
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The approximate conversions are:
Latitude: 1 deg = 110.574 km
Longitude: 1 deg = 111.320*cos(latitude) km
This doesn't fully correct for the Earth's polar flattening - for that you'd probably want a more complicated formula using the WGS84 reference ellipsoid (the model used ...
Visual Studio SP1 error: silverlight_sdk.msi is unavailable
I'm trying to install the SP1 for Visual Studio 2010. I first installed the beta and it worked fine. Then I used the web platform installer to install the SQL CE Compact 4, which I assume installed the full SP1 after (this installation took over 12 hours, so I canceled it). The web platform installe...