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Why is it slower to iterate over a small string than a small list?
...ser to 70% (or more) once a lot of the overhead is removed, for Python 2.
Object creation is not at fault. Neither method creates a new object, as one-character strings are cached.
The difference is unobvious, but is likely created from a greater number of checks on string indexing, with regards to ...
In R, how to get an object's name after it is sent to a function?
...
The old deparse-substitute trick:
a<-data.frame(x=1:10,y=1:10)
test<-function(z){
mean.x<-mean(z$x)
nm <-deparse(substitute(z))
print(nm)
return(mean.x)}
test(a)
#[1] "a" ... this is the side-effect of the print() ...
How to call a Parent Class's method from Child Class in Python?
When creating a simple object hierarchy in Python, I'd like to be able to invoke methods of the parent class from a derived class. In Perl and Java, there is a keyword for this ( super ). In Perl, I might do this:
...
How to search a specific value in all tables (PostgreSQL)?
Is it possible to search every column of every table for a particular value in PostgreSQL?
8 Answers
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Take the content of a list and append it to another list
...
You probably want
list2.extend(list1)
instead of
list2.append(list1)
Here's the difference:
>>> a = range(5)
>>> b = range(3)
>>> c = range(2)
>>> b.append(a)
>>> b
[0, 1, 2, [0, 1...
Sorting multiple keys with Unix sort
I have potentially large files that need to be sorted by 1-n keys. Some of these keys might be numeric and some of them might not be. This is a fixed-width columnar file so there are no delimiters.
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How can I create a copy of an object in Python?
I would like to create a copy of an object. I want the new object to possess all properties of the old object (values of the fields). But I want to have independent objects. So, if I change values of the fields of the new object, the old object should not be affected by that.
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What's the difference between deadlock and livelock?
Can somebody please explain with examples (of code) what is the difference between deadlock and livelock ?
7 Answers
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Git submodule update
I'm not clear on what the following means (from the Git submodule update documentation):
4 Answers
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Get list from pandas DataFrame column headers
...rame will come from user input so I won't know how many columns there will be or what they will be called.
19 Answers
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