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Why do I get AttributeError: 'NoneType' object has no attribute 'something'?
...The sort() method of a list sorts the list in-place, that is, mylist is modified. But the actual return value of the method is None and not the list sorted. So you've just assigned None to mylist. If you next try to do, say, mylist.append(1) Python will give you this error.
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Host 'xxx.xx.xxx.xxx' is not allowed to connect to this MySQL server
...ut this line. For my example, I'll say the actual server is on 10.1.1.7)
Now access the MySQL Database on your actual server (say your remote address is 123.123.123.123 at port 3306 as user 'root' and I want to change permissions on database 'dataentry'. Remember to change the IP Address, Port, a...
What platforms have something other than 8-bit char?
Every now and then, someone on SO points out that char (aka 'byte') isn't necessarily 8 bits .
12 Answers
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Array.push() if does not exist?
How can I push into an array if neither values exist? Here is my array:
23 Answers
23
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TortoiseGit save user authentication / credentials
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Neat. Now how do I use it?
– BlueRaja - Danny Pflughoeft
Aug 16 '13 at 1:59
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Is there a RegExp.escape function in Javascript?
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If you are going to use this function in a loop, it's probably best to make the RegExp object it's own variable var e = /[\-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g; and then your function is return s.replace(e, '\\$&'); This wa...
Expand/collapse section in UITableView in iOS
... headers that are already there will be a pain. Based on the way they work now, I am not sure you can easily get actions out of them. You could set up a cell to LOOK like a header, and setup the tableView:didSelectRowAtIndexPath to manually expand or collapse the section it is in.
I'd store an arra...
PHP script to loop through all of the files in a directory?
...ike to be able to sort the files by name, type or by date created/added/modified. (Think fancy directory "index".) I'd also like to be able to add exclusions to the list of files, such as the script itself or other "system" files. (Like the . and .. "directories".)
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How to select rows from a DataFrame based on column values?
... 2 4
4 foo two 4 8
6 foo one 6 12
7 foo three 7 14
If you have multiple values you want to include, put them in a
list (or more generally, any iterable) and use isin:
print(df.loc[df['B'].isin(['one','three'])])
yields
A B C D
0 foo one 0 0
1 bar o...
How to avoid 'cannot read property of undefined' errors?
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Update:
If you use JavaScript according to ECMAScript 2020 or later, see optional chaining.
TypeScript has added support for optional chaining in version 3.7.
// use it like this
obj?.a?.lot?.of?.properties
Solution for JavaScr...