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How to select rows with one or more nulls from a pandas DataFrame without listing columns explicitly
...0, 0, np.NaN], range(3), range(3)])
>>> df.isnull()
0 1 2
0 False False False
1 False True False
2 False False True
3 False False False
4 False False False
>>> df.isnull().any(axis=1)
0 False
1 True
2 True
3 False
4 False
dtype: bo...
Do htmlspecialchars and mysql_real_escape_string keep my PHP code safe from injection?
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When it comes to database queries, always try and use prepared parameterised queries. The mysqli...
Why can't R's ifelse statements return vectors?
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100
The documentation for ifelse states:
ifelse returns a value with the same
shape as test ...
Counting the number of elements with the values of x in a vector
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18 Answers
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Pandas - How to flatten a hierarchical index in columns
I have a data frame with a hierarchical index in axis 1 (columns) (from a groupby.agg operation):
17 Answers
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calculating the difference in months between two dates
...o months difference? If you say it should yield one, then what about July 31, 2009 and August 1, 2009? Is that a month? Is it simply the difference of the Month values for the dates, or is it more related to an actual span of time? The logic for determining all of these rules is non-trivial, so you'...
Cannot truncate table because it is being referenced by a FOREIGN KEY constraint?
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edited May 23 '17 at 12:10
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answered Oct 31 '08 at 15:08
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Creating a Pandas DataFrame from a Numpy array: How do I specify the index column and column headers
...umns to DataFrame constructor, as in:
>>> pd.DataFrame(data=data[1:,1:], # values
... index=data[1:,0], # 1st column as index
... columns=data[0,1:]) # 1st row as the column names
edit: as in the @joris comment, you may need to change above to np.int_(dat...