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namedtuple and default values for optional keyword arguments
...lds)
>>> Node()
Node(val=None, left=None, right=None)
Order
In all versions of Python, if you set fewer default values than exist in the namedtuple, the defaults are applied to the rightmost parameters. This allows you to keep some arguments as required arguments.
>>> Node.__ne...
Use cases for the 'setdefault' dict method
...e case: Grouping items (in unsorted data, else use itertools.groupby)
# really verbose
new = {}
for (key, value) in data:
if key in new:
new[key].append( value )
else:
new[key] = [value]
# easy with setdefault
new = {}
for (key, value) in data:
group = new.setdefault(k...
How to find the installed pandas version
...trouble with some of pandas functionalities. How do I check what is my installation version?
6 Answers
...
What are “first class” objects?
...as
any other object.
A first class object is an entity that can be dynamically created, destroyed, passed to a function, returned as a value, and have all the rights as other variables in the programming language have.
Depending on the language, this can
imply:
being expressible as ...
Length of generator output [duplicate]
... Fibonacci numbers. You can get as many Fibonacci numbers as you want by calling next().
If you really need to know the number of items there are, then you can't iterate through them linearly one time anyway, so just use a different data structure such as a regular list.
...
Specify JDK for Maven to use
....xml but I don't have a settings.xml . Plus, I don't want to use 1.6 for all maven builds.
14 Answers
...
What does “mro()” do?
...very attribute you get on a class's instance, not just methods, is conceptually looked up along the __mro__, so, if more than one class among the ancestors defines that name, this tells you where the attribute will be found -- in the first class in the __mro__ that defines that name.
...
Delimiters in MySQL
...s it through a programming language API to MySQL. Some other clients like PHPMyAdmin have other methods to specify a non-default delimiter.
Example:
DELIMITER $$
/* This is a complete statement, not part of the procedure, so use the custom delimiter $$ */
DROP PROCEDURE my_procedure$$
/* Now start...
Separation of business logic and data access in django
...de is confusing and, after a certain time, I cease to understand what is really happening.
10 Answers
...
How do I create an HTML table with a fixed/frozen left column and a scrollable body?
... i also used jQuery to .clone() the table, once it has been generated by php+MySQL+ajax, and insert it into a cleaned out div...
– Peter
Mar 6 '18 at 22:27
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