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What are “first class” objects?
...as
any other object.
A first class object is an entity that can be dynamically created, destroyed, passed to a function, returned as a value, and have all the rights as other variables in the programming language have.
Depending on the language, this can
imply:
being expressible as ...
List all files in one directory PHP [duplicate]
What would be the best way to list all the files in one directory with PHP? Is there a $_SERVER function to do this? I would like to list all the files in the usernames/ directory and loop over that result with a link, so that I can just click the hyperlink of the filename to get there. Thanks!
...
Flask-SQLalchemy update a row's information
...e many objects to be updated.
If you want to give add_user permission to all the admins,
rows_changed = User.query.filter_by(role='admin').update(dict(permission='add_user'))
db.session.commit()
Notice that filter_by takes keyword arguments (use only one =) as opposed to filter which takes an e...
Python extending with - using super() Python 3 vs Python 2
Originally I wanted to ask this question , but then I found it was already thought of before...
5 Answers
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Foreign key constraints: When to use ON UPDATE and ON DELETE
... your first link (dev.mysql.com/doc/refman/5.6/en/triggers.html ) to mysql site has changed. It says This includes changes to base tables that underlie updatable views instead of what you pasted i.e. They do not activate for changes in views
– Istiaque Ahmed
D...
Chrome, Javascript, window.open in new tab
...pup’) by specifying options in the 3rd parameter
3. If the window.open call was not part of a user-initiated event, it’ll open in a new window.
4. A “user initiated event” does not have to the same function call – but it must originate in the function invoked by a user click
5. If a use...
putting current class as return type annotation [duplicate]
...e. Instead, they are preserved in __annotations__ in string form. This is called Postponed Evaluation of Annotations, introduced in PEP 563.
Also note:
Deprecation policy
Starting with Python 3.7, a __future__ import is required to use the
described functionality. No warnings are raised...
Java: parse int value from a char
...So e.g. '0' in ascii is 48, '1' is 49, etc. So if you take '2' - '0' you really just get 50 - 48 = 2. Have a look at an ASCII table in order to understand this principle better. Also, 'x' means get the ascii value of the character in Java.
– Kevin Van Ryckegem
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How to include external Python code to use in other files?
...ods in a file, is there a way to include those files in another file, but call them without any prefix (i.e. file prefix)?
...
“Incorrect string value” when trying to insert UTF-8 into MySQL via JDBC?
...ter you can change the column encoding from utf8 to utf8mb4. This encoding allows storage of characters that occupy 4 bytes in UTF-8.
You may also have to set the server property character_set_server to utf8mb4 in the MySQL configuration file. It seems that Connector/J defaults to 3-byte Unicode ot...