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Scala how can I count the number of occurrences in a list
...", "banana", "apple", "oranges", "oranges")
s.groupBy(identity).mapValues(_.size)
giving a Map with a count for each item in the original sequence:
Map(banana -> 1, oranges -> 3, apple -> 3)
The question asks how to find the count of a specific item. With this approach, the solution w...
Forced naming of parameters in Python
...ition to other good answers for Python 2, please consider the following:
__named_only_start = object()
def info(param1,param2,param3,_p=__named_only_start,spacing=10,collapse=1):
if _p is not __named_only_start:
raise TypeError("info() takes at most 3 positional arguments")
return...
Naming convention - underscore in C++ and C# variables
It's common to see a _var variable name in a class field. What does the underscore mean? Is there a reference for all these special naming conventions?
...
How to run code when a class is subclassed? [duplicate]
...on2 you would define the metaclass of a class with
class SuperClass:
__metaclass__ = Watcher
where Watcher is a subclass of type.
In Python3 the syntax has been changed to
class SuperClass(metaclass=Watcher)
Both are equivalent to
Superclass = Watcher(name, bases, clsdict)
where in t...
Check if $_POST exists
I'm trying to check whether a $_POST exists and if it does, print it inside another string, if not, don't print at all.
14 ...
Importing files from different folder
...ers 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, '/path/to/application/app/folder')
import file
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Rename all files in directory from $filename_h to $filename_half?
...
Just use bash, no need to call external commands.
for file in *_h.png
do
mv "$file" "${file/_h.png/_half.png}"
done
Do not add #!/bin/sh
For those that need that one-liner:
for file in *.png; do mv "$file" "${file/_h.png/_half.png}"; done
...
How to iterate through two lists in parallel?
... And to zip until both iterators are
exhausted, you would use
itertools.zip_longest.
Python 2
In Python 2, zip
returns a list of tuples. This is fine when foo and bar are not massive. If they are both massive then forming zip(foo,bar) is an unnecessarily massive
temporary variable, and should be r...
Import a file from a subdirectory?
....org/tutorial/modules.html
In short, you need to put a blank file named
__init__.py
in the "lib" directory.
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What is SYSNAME data type in SQL Server?
...stored procedures etc within SQL Server.
For example, by executing Exec sp_help 'sys.tables' you will see that the column name is defined as sysname this is because the value of this is actually an object in itself (a table)
I would worry too much about it.
It's also worth noting that for those p...