大约有 3,516 项符合查询结果（耗时：0.0134秒） [XML]
What does axis in pandas mean?
...me process on dataframe2.
Basically,
stacking dataframe2 sideways.
E.g arranging books on a bookshelf.
More to it, since arrays are better representations to represent a nested n-dimensional structure compared to matrices! so below can help you more to visualize how axis plays an important rol...
How do you get the list of targets in a makefile?
...ous non-empty lines.
/^# File/,/^# Finished Make data base/
Matches the range of lines in the output that contains all targets (true as of GNU make 3.82) - by limiting parsing to this range, there is no need to deal with false positives from other output sections.
if ($$1 !~ "^[#.]")
Selective...
How to do date/time comparison
... and time - independently. So I might allow an object that occurs within a range of dates so long as it also occurs within a range of times. In this model, I could not simply just select the oldest date, youngest time/latest date, latest time and Unix() seconds compare them. I'd really appreciate an...
How do I create a unique constraint that also allows nulls?
...o use a negative number, to put the "surrogate NULLs" only in the negative range, and the "real values" only in the positive range. Alternately, the following pattern could be used. In table Issue (where IssueID is the PRIMARY KEY), there may or may not be a TicketID, but if there is one, it must be...
How do Python's any and all functions work?
...onsumed. For example,
>>> multiples_of_6 = (not (i % 6) for i in range(1, 10))
>>> any(multiples_of_6)
True
>>> list(multiples_of_6)
[False, False, False]
Here, (not (i % 6) for i in range(1, 10)) is a generator expression which returns True if the current number within...
Counting Chars in EditText Changed Listener
... it.
start: This is the index of where the new text will be inserted. If a range is selected, then it is the beginning index of the range.
count: This is the length of selected text that is going to be replaced. If nothing is selected then count will be 0.
after: this is the length of the text to be...
Binary Data in JSON String. Something better than Base64
...te we start looking at.
As a consequence, if encoding a byte value in the range [0..127] would need only one byte in UTF-8 encoding, encoding a byte value in the range [128..255] would require 2 bytes !
Worse than that. In JSON, control chars, " and \ are not allowed to appear in a string. So the b...
Understanding the map function
...tr(x) for x in iterable ]
b = time.clock() - b
print(a,b)
test1(range(2000000)) # Prints ~1.7e-5s ~8s
test2(range(2000000)) # Prints ~9s ~8s
As you can see initializing the map function takes almost no time at all. However iterating through the map object takes longer than sim...
Parallel foreach with asynchronous lambda
...xception(exceptions);
}
}
}
Usage example:
await Enumerable.Range(1, 10000).ParallelForEachAsync(async (i) =>
{
var data = await GetData(i);
}, maxDegreeOfParallelism: 100);
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How to compare dates in datetime fields in Postgresql?
I have been facing a strange scenario when comparing between dates in postgresql(version 9.2.4 in windows). I have a column in my table say update_date with type 'timestamp without timezone'. Client can search over this field with only date (i.e: 2013-05-03) or date with time (i.e: 2013-05-03 12:20:...