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Regular vs Context Free Grammars
...text-free grammar.
So for a palindrome for instance, is of the form,
S->ABA
A->something
B->something
You can clearly see that palindromes cannot be expressed in regular grammar since it needs to be either right or left linear and as such cannot have a non-terminal on both side.
Since...
Normal arguments vs. keyword arguments
...al arguments passed to foo(), with no limit to how many you can provide.
>>> foo('one', 'two', 'three')
Positional: ('one', 'two', 'three')
Keywords: {}
The **keywords argument will store any keyword arguments:
>>> foo(a='one', b='two', c='three')
Positional: ()
Keywords: {'a':...
What is RemoteSystemsTempFiles in Eclipse?
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You can find Eclipse Remote Systems config in Window -> Preferences -> enter remote systems in search box on top
– nkr1pt
Sep 2 '10 at 13:41
28
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How can I check whether a numpy array is empty or not?
...nsion. For a matrix with n rows and m columns, shape will be (n,m). The length of the shape tuple is therefore the rank, or number of dimensions, ndim.
ndarray.size
the total number of elements of the array. This is equal to the product of the elements of shape.
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Why does C++ not allow inherited friendship?
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What is the point of this answer? at best a dubious although possibly light hearted comment
– DeveloperChris
Apr 12 '16 at 2:15
add a comment
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How to find all occurrences of a substring?
...
>>> help(str.find)
Help on method_descriptor:
find(...)
S.find(sub [,start [,end]]) -> int
Thus, we can build it ourselves:
def find_all(a_str, sub):
start = 0
while True:
start = a_str.find...
How do I check if a Sql server string is null or empty
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SELECT
CASE WHEN LEN(listing.OfferText) > 0 THEN listing.OfferText
ELSE COALESCE(Company.OfferText, '') END
AS Offer_Text,
...
In this example, if listing.OfferText is NULL, the LEN() function should also return NULL, but that's still not > 0....
How do I create a dictionary with keys from a list and values defaulting to (say) zero? [duplicate]
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In python version >= 2.7 and in python 3:
d = {el:0 for el in a}
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Ruby: What is the easiest way to remove the first element from an array?
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a = [0,1,2,3]
a.drop(1)
# => [1, 2, 3]
a
# => [0,1,2,3]
and additionally:
[0,1,2,3].drop(2)
=> [2, 3]
[0,1,2,3].drop(3)
=> [3]
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How to print a date in a regular format?
... use str() because :
print "This is a new day : ", mylist[0] # will work
>>> This is a new day : 2008-11-22
print "This is a new day : " + mylist[0] # will crash
>>> cannot concatenate 'str' and 'datetime.date' objects
print "This is a new day : " + str(mylist[0])
>>> ...