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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...
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
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What is the best way to get the count/length/size of an iterator?
...
Using Guava library, another option is to convert the Iterable to a List.
List list = Lists.newArrayList(some_iterator);
int count = list.size();
Use this if you need also to access the elements of the iterator after getting its size. By using Iterators.size() you...
Memoization in Haskell?
... r = l + s
s' = s * 2
Since we can index, you can just convert a tree into a list:
toList :: Tree a -> [a]
toList as = map (index as) [0..]
You can check the work so far by verifying that toList nats gives you [0..]
Now,
f_tree :: Tree Int
f_tree = fmap (f fastest_f) nat...
How to flatten tree via LINQ?
...n then filter by group using Where(...).
To earn some "points for style", convert Flatten to an extension function in a static class.
public static IEnumerable<MyNode> Flatten(this IEnumerable<MyNode> e) =>
e.SelectMany(c => c.Elements.Flatten()).Concat(e);
To earn more poi...
memory_get_peak_usage() with “real usage”
...ory alignment). It doesn't reflect memory wasted due to blocks not fitting into space remaining in already allocated segments. If you change your example to allocate (1024 * 256) bytes and a 2M limit, the difference of two will become more apparent.
– cleong
Ma...
How do I work around JavaScript's parseInt octal behavior?
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This whole question is about alternatives to parseInt for converting strings to integers. Thus: always.
– Grodriguez
Oct 25 '14 at 9:55
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How to find out what type of a Mat object is with Mat::type() in OpenCV
...u need to know what type an internal OpenCV array is.
Remember OpenCV will convert the jpeg into BGR (or grey scale if you pass '0' to imread) - so it doesn't tell you anything about the original file.
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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
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Does Java have something like C#'s ref and out keywords?
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Like many others, I needed to convert a C# project to Java. I did not find a complete solution on the web regarding out and ref modifiers. But, I was able to take the information I found, and expand upon it to create my own classes to fulfill the requirem...