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Combine two columns of text in pandas dataframe
...arter"]
If one (or both) of the columns are not string typed, you should convert it (them) first,
df["period"] = df["Year"].astype(str) + df["quarter"]
Beware of NaNs when doing this!
If you need to join multiple string columns, you can use agg:
df['period'] = df[['Year', 'quarter', ...]].a...
Coding Practices which enable the compiler/optimizer to make a faster program
...Arithmetic (Edited: applied code format to code fragment, added example)
Convert if statements into boolean assignments. Some processors can conditionally execute instructions without branching:
bool status = true;
status = status && /* first test */;
status = status && /* second...
Vertically align text to top within a UILabel
... Not sure how this will affect the performance if many UILabels are converted to text views.
– ninjaneer
Nov 10 '13 at 12:17
2
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Append a NumPy array to a NumPy array
...
Actually one can always create an ordinary list of numpy arrays and convert it later.
In [1]: import numpy as np
In [2]: a = np.array([[1,2],[3,4]])
In [3]: b = np.array([[1,2],[3,4]])
In [4]: l = [a]
In [5]: l.append(b)
In [6]: l = np.array(l)
In [7]: l.shape
Out[7]: (2, 2, 2)
In [8]...
How do I work around JavaScript's parseInt octal behavior?
...
This whole question is about alternatives to parseInt for converting strings to integers. Thus: always.
– Grodriguez
Oct 25 '14 at 9:55
add a comment
...
How can I find the number of days between two Date objects in Ruby?
... will have a 1 concatenated to the end. yikes! you may want to use to_i to convert the result to an integer
– jwal
Jan 24 '12 at 18:07
9
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What is the purpose of using -pedantic in GCC/G++ compiler?
...o issue warnings in such cases. Using the stricter
-pedantic-errors option converts such diagnostic warnings into errors that will cause compilation
to fail at such points. Only those non-ISO constructs that are required to be flagged by a conforming
compiler will generate warnings or errors.
...
How can I use a C++ library from node.js?
...that returns something like a JavaScript array and have swig automatically convert it for you.
– George
Mar 26 '16 at 3:12
5
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How to round to 2 decimals with Python?
...etting a lot of decimals in the output of this code (Fahrenheit to Celsius converter).
16 Answers
...
How to write a simple Html.DropDownListFor()?
... { 6, "Eggs Benedict"}
};
}
}
In the View convert it to a list for display
@Html.DropDownListFor(m => m.Egg.Keys,
new SelectList(
Model.Egg,
"Key",
"...