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How to write a large buffer into a binary file in C++, fast?
...g), pFile);
}
fclose(pFile);
return 0;
}
I just timed 8GB in 36sec, which is about 220MB/s and I think that maxes out my SSD. Also worth to note, the code in the question used one core 100%, whereas this code only uses 2-5%.
Thanks a lot to everyone.
Update: 5 years have passed it's ...
Python Pandas: Get index of rows which column matches certain value
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473
df.iloc[i] returns the ith row of df. i does not refer to the index label, i is a 0-based index....
Best practices/performance: mixing StringBuilder.append with String.concat
...(s2)
Multiple strings with +
Worth to note that:
String s = s1 + s2 + s3 + ... +sN
is translated to:
String s = new StringBuilder(s1).append(s2).append(s3)...apend(sN).toString();
concat()
String s = s1.concat(s2);
String creates char[] array that can fit both s1 and s2. Copies s1 and s2...
cartesian product in pandas
...import DataFrame, merge
df1 = DataFrame({'key':[1,1], 'col1':[1,2],'col2':[3,4]})
df2 = DataFrame({'key':[1,1], 'col3':[5,6]})
merge(df1, df2,on='key')[['col1', 'col2', 'col3']]
Output:
col1 col2 col3
0 1 3 5
1 1 3 6
2 2 4 5
3 2 4 6
See here...
Reverse of JSON.stringify?
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answered Jun 23 '12 at 18:01
Chase FlorellChase Florell
41.6k5555 gold badges169169 silver badges355355 bronze badges
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How do I run a Python program?
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139
I'm very glad you asked! I was just working on explaining this very thing in our wikibook (whic...
Is there an easy way to strike through text in an app widget?
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ruhalderuhalde
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...
How to get a dependency tree for an artifact?
...e for a given project. But what I need is to see the dependency tree for a 3rd party artifact.
8 Answers
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How to pass in password to pg_dump?
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317
Create a .pgpass file in the home directory of the account that pg_dump will run as. See Postg...
Transpose list of lists
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355
How about
map(list, zip(*l))
--> [[1, 4, 7], [2, 5, 8], [3, 6, 9]]
For python 3.x users ...