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Argparse: Required argument 'y' if 'x' is present
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No, there isn't any option in argparse to make mutually inclusive sets of options.
The simplest way to deal with this would be:
if args.prox and (args.lport is None or args.rport is None):
parser.error("--prox requires --lport an...
How to find the last field using 'cut'
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You could try something like this:
echo 'maps.google.com' | rev | cut -d'.' -f 1 | rev
Explanation
rev reverses "maps.google.com" to be moc.elgoog.spam
cut uses dot (ie '.') as the delimiter, and chooses the first field, which is moc
lastly, we revers...
Is there a read-only generic dictionary available in .NET?
...ad only property. How do I prevent consumers from changing my data? If this were an IList I could simply return it AsReadOnly . Is there something similar I can do with a dictionary?
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Inline comments for Bash?
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My preferred is:
Commenting in a Bash script
This will have some overhead, but technically it does answer your question
echo abc `#put your comment here` \
def `#another chance for a comment` \
xyz etc
And for pipeli...
How do you sort an array on multiple columns?
I have a multidimensional array. The primary array is an array of
16 Answers
16
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Python append() vs. + operator on lists, why do these give different results?
...e to self in that spot (hence the infinite recursion).
The difference here is that the + operation acts specific when you add an array (it's overloaded like others, see this chapter on sequences) by concatenating the element. The append-method however does literally what you ask: append the object o...
How to listen for changes to a MongoDB collection?
...of background job queue system with MongoDB as the data store. How can I "listen" for inserts to a MongoDB collection before spawning workers to process the job? Do I need to poll every few seconds to see if there are any changes from last time, or is there a way my script can wait for inserts to oc...
Java regex email
First of all, I know that using regex for email is not recommended but I gotta test this out.
20 Answers
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boundingRectWithSize for NSAttributedString returning wrong size
...o get the rect for an attributed string, but the boundingRectWithSize call is not respecting the size I pass in and is returning a rect with a single line height as opposed to a large height (it is a long string). I have experimented by passing in a very large value for the height and also 0 as in t...
Converting JSON String to Dictionary Not List
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Your JSON is an array with a single object inside, so when you read it in you get a list with a dictionary inside. You can access your dictionary by accessing item 0 in the list, as shown below:
json1_data = json.loads(json1_str)[0]
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