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Python, compute list difference
...ase on lists with ~6000 strings each showed that this method was almost 100x faster than list comprehensions.
– perrygeo
Feb 1 '14 at 17:01
15
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What is the printf format specifier for bool?
...t when passed down to printf()'s variadic arguments, you can use %d:
bool x = true;
printf("%d\n", x); // prints 1
But why not:
printf(x ? "true" : "false");
or, better:
printf("%s", x ? "true" : "false");
or, even better:
fputs(x ? "true" : "false", stdout);
instead?
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Why are empty strings returned in split() results?
...returned in split() results, you may want to look at the filter function.
Example:
f = filter(None, '/segment/segment/'.split('/'))
s_all = list(f)
returns
['segment', 'segment']
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What does ~~ (“double tilde”) do in Javascript?
...strings, and the result is a number.
In other words, it yields:
function(x) {
if(x < 0) return Math.ceil(x);
else return Math.floor(x);
}
only if x is between -(231) and 231 - 1. Otherwise, overflow will occur and the number will "wrap around".
This may be considered useful to convert a ...
How to merge a list of lists with same type of items to a single list of items?
...
Use the SelectMany extension method
list = listOfList.SelectMany(x => x).ToList();
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How to print a number with commas as thousands separators in JavaScript
...print an integer in JavaScript with commas as thousands separators. For example, I want to show the number 1234567 as "1,234,567". How would I go about doing this?
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Extracting just Month and Year separately from Pandas Datetime column
...ng year and month separately you can do this:
df['year'] = pd.DatetimeIndex(df['ArrivalDate']).year
df['month'] = pd.DatetimeIndex(df['ArrivalDate']).month
or...
df['year'] = df['ArrivalDate'].dt.year
df['month'] = df['ArrivalDate'].dt.month
Then you can combine them or work with them just as ...
What is the difference between i++ and ++i?
...es the variable is incremented, but if you were to take the value of both expressions in exactly the same cases, the result will differ.
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How to validate an email address using a regular expression?
Over the years I have slowly developed a regular expression that validates MOST email addresses correctly, assuming they don't use an IP address as the server part.
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Getting a map() to return a list in Python 3.x
I'm trying to map a list into hex, and then use the list elsewhere. In python 2.6, this was easy:
9 Answers
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