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Behaviour of increment and decrement operators in Python
...ncrement/decrement operator can be applied on a variable (like ++count ). It compiles, but it does not actually change the value of the variable!
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What is the difference between __dirname and ./ in node.js?
...covered the existence of __dirname , and essentially want to know whether it would be smart to convert my ./'s to that, and if so, why that would be a smart idea.
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Can you give a Django app a verbose name for use throughout the admin?
...e dotted path to the appropriate AppConfig subclass to be configured explicitly in INSTALLED_APPS.
Example:
INSTALLED_APPS = [
# ...snip...
'yourapp.apps.YourAppConfig',
]
Then alter your AppConfig as listed below.
Django 1.7
As stated by rhunwicks' comment to OP, this is now possible...
Getting the name of a child class in the parent class (static context)
I'm building an ORM library with reuse and simplicity in mind; everything goes fine except that I got stuck by a stupid inheritance limitation. Please consider the code below:
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Importing files from different folder
....path which includes locations such as the package installation directory (it's actually a little more complex than this, but this covers most cases).
However, you can add to the Python path at runtime:
# some_file.py
import sys
# insert at 1, 0 is the script path (or '' in REPL)
sys.path.insert(1, ...
How to combine two or more querysets in a Django view?
I am trying to build the search for a Django site I am building, and in that search, I am searching in 3 different models. And to get pagination on the search result list, I would like to use a generic object_list view to display the results. But to do that, I have to merge 3 querysets into one.
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How to get a reference to a module inside the module itself?
How can I get a reference to a module from within that module? Also, how can I get a reference to the package containing that module?
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How to find the installed pandas version
I am having trouble with some of pandas functionalities. How do I check what is my installation version?
6 Answers
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How to override the [] operator in Python?
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You need to use the __getitem__ method.
class MyClass:
def __getitem__(self, key):
return key * 2
myobj = MyClass()
myobj[3] #Output: 6
And if you're going to be setting values you'll need to implement the __setitem__ method too, othe...
Delete column from pandas DataFrame
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As you've guessed, the right syntax is
del df['column_name']
It's difficult to make del df.column_name work simply as the result of syntactic limitations in Python. del df[name] gets translated to df.__delitem__(name) under the covers by Python.
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