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Integrate ZXing in Android Studio
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234
I was integrating ZXING into an Android application and there were no good sources for the inp...
How to match a String against string literals in Rust?
... => println!("0"),
"b" => println!("1"),
"c" => println!("2"),
_ => println!("something else!"),
}
There's also an as_str method as of Rust 1.7.0:
match stringthing.as_str() {
"a" => println!("0"),
"b" => println!("1"),
"c" => println!("2"),
_ =>...
How exactly does a generator comprehension work?
...em out of the expression, one by one.
>>> my_list = [1, 3, 5, 9, 2, 6]
>>> filtered_list = [item for item in my_list if item > 3]
>>> print(filtered_list)
[5, 9, 6]
>>> len(filtered_list)
3
>>> # compare to generator expression
...
>>> filte...
What is the difference between ndarray and array in numpy?
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232
numpy.array is just a convenience function to create an ndarray; it is not a class itself.
...
Multiple glibc libraries on a single host
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234
It is very possible to have multiple versions of glibc on the same system (we do that every da...
dplyr: “Error in n(): function should not be called directly”
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120
I presume you have dplyr and plyr loaded in the same session. dplyr is not plyr. ddply is not a...
Error: Jump to case label
...In the following code, if foo equals 1, everything is ok, but if it equals 2, we'll accidentally use the i variable which does exist but probably contains garbage.
switch(foo) {
case 1:
int i = 42; // i exists all the way to the end of the switch
dostuff(i);
break;
case 2:
dostu...
What does the star operator mean, in a function call?
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932
The single star * unpacks the sequence/collection into positional arguments, so you can do this:...
how do you filter pandas dataframes by multiple columns
... sub-statements with ():
males = df[(df[Gender]=='Male') & (df[Year]==2014)]
To store your dataframes in a dict using a for loop:
from collections import defaultdict
dic={}
for g in ['male', 'female']:
dic[g]=defaultdict(dict)
for y in [2013, 2014]:
dic[g][y]=df[(df[Gender]==g) &...
Nested JSON objects - do I have to use arrays for everything?
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204
You don't need to use arrays.
JSON values can be arrays, objects, or primitives (numbers or s...