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String concatenation in Ruby
...; but that is not the usual way
With string interpolation
source = "#{ROOT_DIR}/#{project}/App.config"
with +
source = "#{ROOT_DIR}/" + project + "/App.config"
The second method seems to be more efficient in term of memory/speed from what I've seen (not measured though). All three methods will...
Pure JavaScript Send POST Data Without a Form
... socket, SocketServer, BaseHTTPServer
import os, traceback, sys, json
log_lock = threading.Lock()
log_next_thread_id = 0
# Local log functiondef
def Log(module, msg):
with log_lock:
thread = threading.current_thread().__name__
msg = "%s %s: %s" % (module, thread...
How to get instance variables in Python?
...
Every object has a __dict__ variable containing all the variables and its values in it.
Try this
>>> hi_obj = hi()
>>> hi_obj.__dict__.keys()
share...
What is the fastest way to check if a class has a function defined?
...tr() to get the attribute, and callable() to verify it is a method:
invert_op = getattr(self, "invert_op", None)
if callable(invert_op):
invert_op(self.path.parent_op)
Note that getattr() normally throws exception when the attribute doesn't exist. However, if you specify a default value (None...
private[this] vs private
...nt type T occurs in contravariant position in type Option[T] of value value_=
class Holder[+T] (initialValue: Option[T]) {
This error occurs because value is a mutable variable on the covariant type T (+T) which is normally a problem unless marked as private to the instance with private[this...
How do I log a Python error with debug information?
...
The exception method simply calls error(message, exc_info=1). As soon as you pass exc_info to any of the logging methods from an exception context, you will get a traceback.
– Helmut Grohne
Jun 25 '13 at 18:46
...
Python nested functions variable scoping [duplicate]
...When I run your code I get this error:
UnboundLocalError: local variable '_total' referenced before assignment
This problem is caused by this line:
_total += PRICE_RANGES[key][0]
The documentation about Scopes and Namespaces says this:
A special quirk of Python is that – if no global st...
How to suppress “unused parameter” warnings in C?
...
I'm using #define UNUSED(...) (void)(__VA_ARGS__) which allows me to apply this to multiple variables.
– Matthew Mitchell
Nov 13 '14 at 18:31
...
Facebook Callback appends '#_=_' to Return URL
Facebook callback has started appending #_=_ hash underscore to the Return URL
23 Answers
...
The tilde operator in Python
...s operator.invert. To support this operator in your own class, give it an __invert__(self) method.
>>> import operator
>>> class Foo:
... def __invert__(self):
... print 'invert'
...
>>> x = Foo()
>>> operator.invert(x)
invert
>>> ~x
invert
Any ...