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python pandas: Remove duplicates by columns A, keeping the row with the highest value in column B
... want to drop duplicates, keeping the row with the highest value in column B.
12 Answers
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Delete an element from a dictionary
...s the existing dictionary so the contents of the dictionary changes for anybody else who has a reference to the same instance. To return a new dictionary, make a copy of the dictionary:
def removekey(d, key):
r = dict(d)
del r[key]
return r
The dict() constructor makes a shallow copy....
What is a word boundary in regex?
...ic output, among other purposes) and cannot find a precise definition of \b ("word boundary"). I had assumed that -12 would be an "integer word" (matched by \b\-?\d+\b ) but it appears that this does not work. I'd be grateful to know of ways of matching space-separated numbers.
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How to define an enumerated type (enum) in C?
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Declaring an enum variable is done like this:
enum strategy {RANDOM, IMMEDIATE, SEARCH};
enum strategy my_strategy = IMMEDIATE;
However, you can use a typedef to shorten the variable declarations, like so:
typedef enum {RANDOM, IMMEDIATE, SEARC...
Append a NumPy array to a NumPy array
I have a numpy_array. Something like [ a b c ] .
9 Answers
9
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How does this code generate the map of India?
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The long string is simply a binary sequence converted to ASCII. The first for statement makes b start out at 10, and the [b+++21] after the string yields 31. Treating the string as an array, offset 31 is the start of the "real" data in the string (the...
Converting bool to text in C++
Maybe this is a dumb question, but is there any way to convert a boolean value to a string such that 1 turns to "true" and 0 turns to "false"? I could just use an if statement, but it would be nice to know if there is a way to do that with the language or standard libraries. Plus, I'm a pedant. :...
Convert list of dictionaries to a pandas DataFrame
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cs95
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answered Dec 17 '13 at 15:35
jorisjoris
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Bash tool to get nth line from a file
Is there a "canonical" way of doing that? I've been using head -n | tail -1 which does the trick, but I've been wondering if there's a Bash tool that specifically extracts a line (or a range of lines) from a file.
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Pandas: drop a level from a multi-level column index?
...ltiIndex.droplevel:
>>> cols = pd.MultiIndex.from_tuples([("a", "b"), ("a", "c")])
>>> df = pd.DataFrame([[1,2], [3,4]], columns=cols)
>>> df
a
b c
0 1 2
1 3 4
[2 rows x 2 columns]
>>> df.columns = df.columns.droplevel()
>>> df
b c
0 ...