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How to make PyCharm always show line numbers
I cannot seem to be able to find the setting to enable line numbers for all files, but I have to always right click and enable this on per file basis.
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What does the line “#!/bin/sh” mean in a UNIX shell script?
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It's called a shebang, and tells the parent shell which interpreter should be used to execute the script.
e.g.
#!/usr/bin/perl <--perl script'
#!/usr/bin/php <-- php script
#!/bin/false <--- do-nothing script, because ...
How to flatten only some dimensions of a numpy array
...an take -1 as an argument, meaning "total array size divided by product of all other listed dimensions":
e.g. to flatten all but the last dimension:
>>> arr = numpy.zeros((50,100,25))
>>> new_arr = arr.reshape(-1, arr.shape[-1])
>>> new_arr.shape
# (5000, 25)
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Turning off “created by” stamp when generating files in IntelliJ
...nclude Templates in the popup action search dialog. There should be a tab called Includes on which you will find the Java and ActionScript file types, and the text can simply be removed completely if you like.
But, in more recent versions of IntelliJ things have got quite a bit easier. The first ti...
Redis strings vs Redis hashes to represent JSON: efficiency?
I want to store a JSON payload into redis. There's really 2 ways I can do this:
3 Answers
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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 and --rport.")
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Git diff between current branch and master but not including unmerged master commits
I want a diff of all changes in a branch that is not merged to master yet.
3 Answers
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Does MySQL ignore null values on unique constraints?
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Yes, MySQL allows multiple NULLs in a column with a unique constraint.
CREATE TABLE table1 (x INT NULL UNIQUE);
INSERT table1 VALUES (1);
INSERT table1 VALUES (1); -- Duplicate entry '1' for key 'x'
INSERT table1 VALUES (NULL);
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Specifying colClasses in the read.csv
... the read.csv function in R. In my data, the first column "time" is basically a character vector while the rest of the columns are numeric.
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Sorting related items in a Django template
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I added an alternate solution for you. It should allow you the flexibility you need.
– tawmas
Jun 30 '11 at 22:39
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