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How to pass a user defined argument in scrapy spider
...www.example.com/{category}'] # py36
super().__init__(**kwargs) # python3
def parse(self, response)
self.log(self.domain) # system
Taken from the Scrapy doc: http://doc.scrapy.org/en/latest/topics/spiders.html#spider-arguments
Update 2013: Add second argument
Update 2015: ...
How to convert Nonetype to int or string?
...erally a number, but could be None . I want to divide it by a number, but Python raises:
10 Answers
...
How to check if all of the following items are in a list?
...
Operators like <= in Python are generally not overriden to mean something significantly different than "less than or equal to". It's unusual for the standard library does this--it smells like legacy API to me.
Use the equivalent and more clearl...
matplotlib Legend Markers Only Once
...
I like to change my matplotlib rc parameters dynamically in every python script. To achieve this goal I simply use somthing like that at the beginning of my python files.
from pylab import *
rcParams['legend.numpoints'] = 1
This will apply to all plots generated from my python file.
EDI...
Verify version of rabbitmq
..._properties.items():
print k, v
Save as checkVersion.py and run with python checkVersion.py dev.rabbitmq.com:
% python checkVersion.py dev.rabbitmq.com
information Licensed under the MPL. See http://www.rabbitmq.com/
product RabbitMQ
copyright Copyright (C) 2007-2011 VMware, Inc.
capabilitie...
Why does (1 in [1,0] == True) evaluate to False?
...
Python actually applies comparison operator chaining here. The expression is translated to
(1 in [1, 0]) and ([1, 0] == True)
which is obviously False.
This also happens for expressions like
a < b < c
which tran...
How to trick an application into thinking its stdout is a terminal, not a pipe
... is amazing. I needed this for an extremely rare use case with an embedded Python library within an executable that is run within Wine. When I ran in a terminal it worked but when I ran the .desktop file I created it would always crash because Py_Initialize didn't see proper stdin/stderr.
...
How to extract the decision rules from scikit-learn decision-tree?
...at(indent, tree_.value[node])
recurse(0, 1)
This prints out a valid Python function. Here's an example output for a tree that is trying to return its input, a number between 0 and 10.
def tree(f0):
if f0 <= 6.0:
if f0 <= 1.5:
return [[ 0.]]
else: # if f0 > 1.5
...
Why doesn't Objective-C support private methods?
...
More python being "obj-c-ic" :). Guido was quite proactive in maintaining Python on NeXT systems, including creating the 1st version of PyObjC. Thus, ObjC did influence python somewhat.
– bbum
...
What's so great about Lisp? [closed]
...You could in theory embed any language into Lisp like Rust, Ruby, C, Java, Python, Erlang. So the s-expression version of Python (Hy) and the of Rust is called (Risp) [although I don't know how stable these are]. If you write code in Hy instead of Python you have the ability of macros and structur...