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Do the parentheses after the type name make a difference with new?
If 'Test' is an ordinary class, is there any difference between:
6 Answers
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Sample random rows in dataframe
...ruggling to find the appropriate function that would return a specified number of rows picked up randomly without replacement from a data frame in R language? Can anyone help me out?
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Why are elementwise additions much faster in separate loops than in a combined loop?
Suppose a1 , b1 , c1 , and d1 point to heap memory and my numerical code has the following core loop.
10 Answers
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Listing all permutations of a string/integer
...f interviews though) is to take a string or an integer and list every possible permutation.
28 Answers
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Return anonymous type results?
Using the simple example below, what is the best way to return results from multiple tables using Linq to SQL?
16 Answers
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count the frequency that a value occurs in a dataframe column
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Use groupby and count:
In [37]:
df = pd.DataFrame({'a':list('abssbab')})
df.groupby('a').count()
Out[37]:
a
a
a 2
b 3
s 2
[3 rows x 1 columns]
See the online docs: http://pandas.pydata.org/pandas-docs/stable/groupby.htm...
SQL JOIN vs IN performance?
...g a JOIN or an IN will give me the correct results... Which typically has better performance and why? How much does it depend on what database server you are running? (FYI I am using MSSQL)
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Fast way of counting non-zero bits in positive integer
I need a fast way to count the number of bits in an integer in python.
My current solution is
9 Answers
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Simultaneously merge multiple data.frames in a list
...o merge. The issue here is that each data.frame differs in terms of the number of rows and columns, but they all share the key variables (which I've called "var1" and "var2" in the code below). If the data.frames were identical in terms of columns, I could merely rbind , for which plyr's rbind...
Math - mapping numbers
How do I map numbers, linearly, between a and b to go between c and d.
9 Answers
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