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How to filter Pandas dataframe using 'in' and 'not in' like in SQL
...g.isin(somewhere)
Or for "NOT IN": ~something.isin(somewhere)
As a worked example:
import pandas as pd
>>> df
country
0 US
1 UK
2 Germany
3 China
>>> countries_to_keep
['UK', 'China']
>>> df.country.isin(countries_to_keep)
0 False
1 True
2 ...
How to remove leading and trailing zeros in a string? Python
...12-n\n"," 12091231000-n00000","alphanum0000", "00alphanum"]
pred = lambda x: x in {"0", "\n", " "}
list("".join(mit.strip(i, pred)) for i in iterables)
# ['231512-n', '12091231000-n', 'alphanum', 'alphanum']
Details
Notice, here we strip both leading and trailing "0"s among other elements that...
Python nested functions variable scoping [duplicate]
...the statement b = 4 commented out, this code outputs 0 1, just what you'd expect.
But if you uncomment that line, on the line print b, you get the error
UnboundLocalError: local variable 'b' referenced before assignment
It seems mysterious that the presence of b = 4 might somehow make b disappea...
Convert light frequency to RGB?
...
Here's a detailed explanation of the entire conversion process: http://www.fourmilab.ch/documents/specrend/. Source code included!
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Is it possible to set code behind a resource dictionary in WPF for event handling?
Is it possible to set code behind a resource dictionary in WPF. For example in a usercontrol for a button you declare it in XAML. The event handling code for the button click is done in the code file behind the control. If I was to create a data template with a button how can I write the event handl...
How to check if all list items have the same value and return it, or return an “otherValue” if they
...
var val = yyy.First().Value;
return yyy.All(x=>x.Value == val) ? val : otherValue;
Cleanest way I can think of. You can make it a one-liner by inlining val, but First() would be evaluated n times, doubling execution time.
To incorporate the "empty set" behavior ...
ValueError: setting an array element with a sequence
... array from a list that isn't shaped like a multi-dimensional array. For example
numpy.array([[1,2], [2, 3, 4]])
or
numpy.array([[1,2], [2, [3, 4]]])
will yield this error message, because the shape of the input list isn't a (generalised) "box" that can be turned into a multidimensional array...
rgdal package installation
The issue here is not exactly how to plot maps through R, as I have found already a pretty nice example here , but rather how to make it work. In fact, I am unable to load library rgdal :
...
'and' (boolean) vs '&' (bitwise) - Why difference in behavior with lists vs numpy arrays?
What explains the difference in behavior of boolean and bitwise operations on lists vs NumPy arrays?
8 Answers
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How to take all but the last element in a sequence using LINQ?
...e;
T item = default(T);
do {
hasRemainingItems = it.MoveNext();
if (hasRemainingItems) {
if (!isFirst) yield return item;
item = it.Current;
isFirst = false;
}
} while (hasRemainingItems);
}
static void Main(string[] args) {
...