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JavaScript variable number of arguments to function
...rty. This includes the arguments object. Knowing this, and that the method concat returns a copy of the 'array' it's called on, we can easily convert the arguments object to a real array like this: var args = [].concat.call(arguments). Some people prefer to use Array.prototype.concat.call instead, b...
Pandas groupby: How to get a union of strings
...is!
3 3 0.463468 a
4 4 0.643961 random
sum by default concatenates
In [9]: df.groupby('A')['C'].apply(lambda x: x.sum())
Out[9]:
A
1 Thisstring
2 is!
3 a
4 random
dtype: object
You can do pretty much what you want
In [11]: df.groupby('A')['C'...
Transposing a 2D-array in JavaScript
...rix.reduce((prev, next) => next.map((item, i) =>
(prev[i] || []).concat(next[i])
), []);
}
Lodash/Underscore by marcel
function tranpose(matrix) {
return _.zip(...matrix);
}
// Without spread operator.
function transpose(matrix) {
return _.zip.apply(_, [[1,2,3], [1,2,3], [1,2,3]]...
Creating an empty Pandas DataFrame, then filling it?
...ire handling the index appropriately).
Things you should NOT do
append or concat inside a loop
Here is the biggest mistake I've seen from beginners:
df = pd.DataFrame(columns=['A', 'B', 'C'])
for a, b, c in some_function_that_yields_data():
df = df.append({'A': i, 'B': b, 'C': c}, ignore_index=...
How do I create a PDO parameterized query with a LIKE statement?
...e LIKE with % partial matching for MySQL databases: WHERE column_name LIKE CONCAT('%', :dangerousstring, '%')
where the named parameter is :dangerousstring.
In other words, use explicitly unescaped % signs in your own query that are separated and definitely not the user input.
Edit: Concatenati...
When to use StringBuilder in Java [duplicate]
...is supposed to be generally preferable to use a StringBuilder for string concatenation in Java. Is this always the case?
...
How do I concatenate multiple C++ strings on one line?
C# has a syntax feature where you can concatenate many data types together on 1 line.
24 Answers
...
Return multiple columns from pandas apply()
... series, new columns exist):')
df_test = create_new_df_test()
df_test = pd.concat([df_test, pd.DataFrame(columns=['size_kb', 'size_mb', 'size_gb'])])
%timeit result = df_test.apply(sizes_pass_series_return_series, axis=1)
print('\nPandafied (pass series, return tuple, new columns dont exist):')
df_...
how to split the ng-repeat data with three columns using bootstrap
...d format:
$scope.$watch('chunkedData', function(val) {
$scope.data = [].concat.apply([], val);
}, true); // deep watch
Many people prefer to accomplish this in the view with a filter. This is possible, but should only be used for display purposes! If you add inputs within this filtered view, it...
Insert a row to pandas dataframe
...
Not sure how you were calling concat() but it should work as long as both objects are of the same type. Maybe the issue is that you need to cast your second vector to a dataframe? Using the df that you defined the following works for me:
df2 = pd.DataFra...