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Python - When to use file vs open
... always use open().
As the documentation states:
When opening a file, it's preferable
to use open() instead of invoking this
constructor directly. file is more
suited to type testing (for example,
writing "isinstance(f, file)").
Also, file() has been removed since Python 3.0.
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What is this 'Lambda' everyone keeps speaking of?
... is this 'Lambda' everyone keeps speaking of? A lot of people seem to love it, but all I can gather from it is it is just a way of cramming lots of lines of code into a single expression.
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How to rename a single column in a data.frame?
I know if I have a data frame with more than 1 column, I can use
20 Answers
20
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How do you remove duplicates from a list whilst preserving order?
...alling seen.add? Python is a dynamic language, and resolving seen.add each iteration is more costly than resolving a local variable. seen.add could have changed between iterations, and the runtime isn't smart enough to rule that out. To play it safe, it has to check the object each time.
If you pla...
Delete all tags from a Git repository
I want to delete all the tags from a Git repository. How can I do that?
11 Answers
11
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What does mysql error 1025 (HY000): Error on rename of './foo' (errorno: 150) mean?
...the column name, but instead you would have to find the name used to index it. To find that, issue the following select:
SHOW CREATE TABLE region;
This should show you the name of the index, something like this:
CONSTRAINT region_ibfk_1 FOREIGN
KEY (country_id) REFERENCES
country (id) ...
Using pg_dump to only get insert statements from one table within database
... for a way to get all rows as INSERT statements from one specific table within a database using pg_dump in PostgreSQL.
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How to have stored properties in Swift, the same way I had on Objective-C?
I am switching an application from Objective-C to Swift, which I have a couple of categories with stored properties, for example:
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Cartesian product of multiple arrays in JavaScript
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2020 Update: 1-line (!) answer with vanilla JS
Original 2017 Answer: 2-line answer with vanilla JS:
(see updates below)
All of the answers here are overly complicated, most of them take 20 lines of code or even more.
This example uses just two lines of vani...
How do I find where JDK is installed on my windows machine?
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Updated the answer with Linux/Unix/Mac OS X and Windows examples.
– Pablo Santa Cruz
Jan 13 '11 at 14:32
129
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