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Count how many records are in a CSV Python?
...aranteed to be a fixed size, so the only way to count them is to read them all.
– Martijn Pieters♦
Apr 19 '13 at 15:55
1
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Longest line in a file
...ing for a simple way to find the length of the longest line in a file. Ideally, it would be a simple bash shell command instead of a script.
...
How to use clock() in C++
How do I call clock() in C++ ?
7 Answers
7
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What is a memory fence?
...ead/writes occur in the order you expect. For example a 'full fence' means all read/writes before the fence are comitted before those after the fence.
Note memory fences are a hardware concept. In higher level languages we are used to dealing with mutexes and semaphores - these may well be implemen...
Python dictionary: Get list of values for list of keys
...n list-comp:
Build list and throw exception if key not found: map(mydict.__getitem__, mykeys)
Build list with None if key not found: map(mydict.get, mykeys)
Alternatively, using operator.itemgetter can return a tuple:
from operator import itemgetter
myvalues = itemgetter(*mykeys)(mydict)
# use ...
Facebook Callback appends '#_=_' to Return URL
Facebook callback has started appending #_=_ hash underscore to the Return URL
23 Answers
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Post-install script with Python setuptools
...from setuptools.command.install import install
from subprocess import check_call
class PreDevelopCommand(develop):
"""Pre-installation for development mode."""
def run(self):
check_call("apt-get install this-package".split())
develop.run(self)
class PreInstallCommand(insta...
Adding :default => true to boolean in existing Rails column
...
change_column is a method of ActiveRecord::Migration, so you can't call it like that in the console.
If you want to add a default value for this column, create a new migration:
rails g migration add_default_value_to_show_attribute
Then in the migration created:
# That's the more generic way t...
Build Eclipse Java Project from Command Line
...ore.aptBuild
It uses the jdt apt plugin to build your workspace automatically. This is also known as a 'Headless Build'. Damn hard to figure out. If you're not using a win32 exe, you can try this:
java -cp startup.jar -noSplash -data "D:\Source\MyProject\workspace" -application org.eclipse.jdt....
How to capture stdout output from a Python function call?
...ager:
from io import StringIO
import sys
class Capturing(list):
def __enter__(self):
self._stdout = sys.stdout
sys.stdout = self._stringio = StringIO()
return self
def __exit__(self, *args):
self.extend(self._stringio.getvalue().splitlines())
del se...