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In javascript, is an empty string always false as a boolean?
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Yes. All false, 0, empty strings '' and "", NaN, undefined, and null are always evaluated as false; everything else is true.
And in your example, b is false after evaluation. (I think you mistakenly wrote true)
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Django gives Bad Request (400) when DEBUG = False
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The ALLOWED_HOSTS list should contain fully qualified host names, not urls. Leave out the port and the protocol. If you are using 127.0.0.1, I would add localhost to the list too:
ALLOWED_HOSTS = ['127.0.0.1', 'localhost']
You...
How can I pretty-print JSON in a shell script?
...ou can use
curl http://my_url/ | python -m json.tool
For convenience in all of these cases you can make an alias:
alias prettyjson='python -m json.tool'
For even more convenience with a bit more typing to get it ready:
prettyjson_s() {
echo "$1" | python -m json.tool
}
prettyjson_f() {...
numpy: most efficient frequency counts for unique values in an array
....org/doc/numpy/reference/generated/numpy.bincount.html
import numpy as np
x = np.array([1,1,1,2,2,2,5,25,1,1])
y = np.bincount(x)
ii = np.nonzero(y)[0]
And then:
zip(ii,y[ii])
# [(1, 5), (2, 3), (5, 1), (25, 1)]
or:
np.vstack((ii,y[ii])).T
# array([[ 1, 5],
[ 2, 3],
[ 5, ...
How to escape JSON string?
...r deserializing - rater it is used when you want to create a JSON text manually and you have a C# string and need to gets its proper representation as a text.
– Dror Harari
Dec 30 '14 at 22:50
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Convert from List into IEnumerable format
How shall I do in order to convert _Book_List into IEnumerable format?
6 Answers
6...
How to rollback a specific migration?
...nt to go back.
For example:
rake db:rollback STEP=5
Will also rollback all the migration that happened later (4, 3, 2 and also 1).
To roll back all migrations back to (and including) a target migration, use: (This corrected command was added AFTER all the comments pointing out the error in the ...
How to convert a string of bytes into an int?
... use the struct module to do this:
>>> struct.unpack("<L", "y\xcc\xa6\xbb")[0]
3148270713L
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Remove ALL white spaces from text
... other RegEx modifiers available in JavaScript here.
If you want to match all whitespace, and not just the literal space character, use \s instead:
.replace(/\s/g,'')
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How to sum all the values in a dictionary?
... I don't know if you love python, if you love python 3, or if really are referring to a python 2
– Lucas Vazquez
Sep 23 '19 at 20:19
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