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How to know if an object has an attribute in Python
...n is that, if the property is likely to be there most of the time, simply call it and either let the exception propagate, or trap it with a try/except block. This will likely be faster than hasattr. If the property is likely to not be there most of the time, or you're not sure, using hasattr will pr...
Combining two expressions (Expression)
...m);
}
Starting from .NET 4.0, there is the ExpressionVisitor class which allows you to build expressions that are EF safe.
public static Expression<Func<T, bool>> AndAlso<T>(
this Expression<Func<T, bool>> expr1,
Expression<Func<T, bool>&...
Using Python String Formatting with Lists
...rmat with print() to iterate a list.
How about this (python 3.x):
sample_list = ['cat', 'dog', 'bunny', 'pig']
print("Your list of animals are: {}, {}, {} and {}".format(*sample_list))
Read the docs here on using format().
...
Python: most idiomatic way to convert None to empty string?
...
If you actually want your function to behave like the str() built-in, but return an empty string when the argument is None, do this:
def xstr(s):
if s is None:
return ''
return str(s)
...
Overloading Macro on Number of Arguments
...
Simple as:
#define GET_MACRO(_1,_2,_3,NAME,...) NAME
#define FOO(...) GET_MACRO(__VA_ARGS__, FOO3, FOO2)(__VA_ARGS__)
So if you have these macros:
FOO(World, !) # expands to FOO2(World, !)
FOO(foo,bar,baz) # expands to FOO3(foo,bar...
Python: try statement in a single line
...ther dynamic languages. The safer way (and the prevailing style) is to set all variables to something. If they might not get set, set them to None first (or 0 or '' or something if it is more applicable.)
If you do assign all the names you are interested in first, you do have options.
The best...
Why does struct alignment depend on whether a field type is primitive or user-defined?
... The documentation of StructLayoutAttribute is pretty interesting. Basically, only blittable types are controlled through StructLayout in managed memory. Interesting, never knew that.
– Michael Stum♦
Jul 15 '14 at 7:01
...
Does Go have “if x in” construct similar to Python?
...ion without separate methods for every single type
– Allen
May 13 '15 at 4:33
29
It could be done...
What's the proper way to install pip, virtualenv, and distribute for Python?
...estion 4314376 , I recommended using ez_setup so that you could then install pip and virtualenv as follows:
15 Answer...
How do you express binary literals in Python?
... memory.
Note that leading zeros in a non-zero decimal number are not allowed.
This is for disambiguation with C-style octal literals, which Python
used before version 3.0.
Some examples of integer literals:
7 2147483647 0o177 0b100110111
3 7922816251...