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How do I merge two dictionaries in a single expression in Python (taking union of dictionaries)?
...ssion.
Note that we can merge in with literal notation as well:
z = {**x, 'foo': 1, 'bar': 2, **y}
and now:
>>> z
{'a': 1, 'b': 3, 'foo': 1, 'bar': 2, 'c': 4}
It is now showing as implemented in the release schedule for 3.5, PEP 478, and it has now made its way into What's New in Python 3...
R: Comment out block of code [duplicate]
...just put # signs in front of every line (possibly with editor shortcuts).
foo <- scan(what="character")
These are comments
These are still comments
Can also be code:
x <- 1:10
One line must be blank
rm(foo)
share
...
How do I call one constructor from another in Java?
...
Yes, it is possible:
public class Foo {
private int x;
public Foo() {
this(1);
}
public Foo(int x) {
this.x = x;
}
}
To chain to a particular superclass constructor instead of one in the same class, use super instead of...
How to drop columns by name in a data frame
...t) %in% c("z","u"))] ## works as expected
dat[ , -which(names(dat) %in% c("foo","bar"))] ## deletes all columns! Probably not what you wanted...
Instead use subset or the ! function:
dat[ , !names(dat) %in% c("z","u")] ## works as expected
dat[ , !names(dat) %in% c("foo","bar")] ## returns the un...
Linq to SQL how to do “where [column] in (list of values)”
...
Use
where list.Contains(item.Property)
Or in your case:
var foo = from codeData in channel.AsQueryable<CodeData>()
where codeIDs.Contains(codeData.CodeId)
select codeData;
But you might as well do that in dot notation:
var foo = channel.AsQueryable<Code...
WiX tricks and tips
...ant it to appear in Add/Remove Programs-->
<?define ProductName = "Foo 64 Bit [Live]" ?>
<?else ?>
<?define ProductName = "Foo [Live]" ?>
<?endif ?>
<!-- Directory name used as default installation location -->
<?define InstallName = "Foo [Live]" ?>
<...
How to determine when a Git branch was created?
...
Use
git show --summary `git merge-base foo master`
If you’d rather see it in context using gitk, then use
gitk --all --select-commit=`git merge-base foo master`
(where foo is the name of the branch you are looking for.)
...
Difference between __getattr__ vs __getattribute__
...ample based on Ned Batchelder's explanation.
__getattr__ example:
class Foo(object):
def __getattr__(self, attr):
print "looking up", attr
value = 42
self.__dict__[attr] = value
return value
f = Foo()
print f.x
#output >>> looking up x 42
f.x = 3
pr...
Checking that a List is not empty in Hamcrest
...;
E.g. if you run
assertEquals(new ArrayList<>(0), Arrays.asList("foo", "bar");
you get
java.lang.AssertionError
Expected :[]
Actual :[foo, bar]
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UnboundLocalError on local variable when reassigned after first use
...
The best example that makes it clear is:
bar = 42
def foo():
print bar
if False:
bar = 0
when calling foo() , this also raises UnboundLocalError although we will never reach to line bar=0, so logically local variable should never be created.
The mystery lies i...