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How to apply a function to two columns of Pandas dataframe
Suppose I have a df which has columns of 'ID', 'col_1', 'col_2' . And I define a function :
12 Answers
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Creating a singleton in Python
...mple implementation:
class Singleton(type):
_instances = {}
def __call__(cls, *args, **kwargs):
if cls not in cls._instances:
cls._instances[cls] = super(Singleton, cls).__call__(*args, **kwargs)
return cls._instances[cls]
class Logger(object):
__meta...
error: ‘uint16_t’ does not name a type - C/C++ - 清泛网 - 专注C/C++及内核技术
...ght notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHA...
Enable access control on simple HTTP server
...mport sys
class CORSRequestHandler (SimpleHTTPRequestHandler):
def end_headers (self):
self.send_header('Access-Control-Allow-Origin', '*')
SimpleHTTPRequestHandler.end_headers(self)
if __name__ == '__main__':
test(CORSRequestHandler, HTTPServer, port=int(sys.argv[1]) if le...
Why is printing to stdout so slow? Can it be sped up?
...ing I decided to look into it and was quite surprised to find that almost all the time spent is waiting for the terminal to process the results.
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How can I alter a primary key constraint using SQL syntax?
...y constraint name, use query found here to look it up (or look up and drop all at once). http://stackoverflow.com/a/13948609/945875
– Justin
Dec 19 '13 at 20:06
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What is Java String interning?
...p://docs.oracle.com/javase/7/docs/api/java/lang/String.html#intern()
Basically doing String.intern() on a series of strings will ensure that all strings having same contents share same memory. So if you have list of names where 'john' appears 1000 times, by interning you ensure only one 'john' is a...
Accessing class variables from a list comprehension in the class definition
...ing a newly created local namespace and the original global namespace. (Usually, the suite contains only function definitions.) When the class’s suite finishes execution, its execution frame is discarded but its local namespace is saved. [4] A class object is then created using the inheritance lis...
TypeScript typed array usage
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You have an error in your syntax here:
this._possessions = new Thing[100]();
This doesn't create an "array of things". To create an array of things, you can simply use the array literal expression:
this._possessions = [];
Of the array constructor if you want to se...
What is the most efficient way to loop through dataframes with pandas? [duplicate]
...Note that iterrows is very slow (it converts every row to a series, potentially messing with your data types). When you need an iterator, better to use itertuples
– joris
Jul 29 '15 at 15:46
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