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UnboundLocalError on local variable when reassigned after first use
... The variable scope decision is made by the compiler, which normally runs once when you first start the program. However it is worth keeping in mind that the compiler might also run later if you have "eval" or "exec" statements in your program.
– Greg Hewgill
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Understanding Linux /proc/id/maps
... a good resource for seeing the details. Unfortunately I don't understand all the columns and entries.
3 Answers
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Best way to structure a tkinter application? [closed]
The following is the overall structure of my typical python tkinter program.
7 Answers
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Why does C++ require a user-provided default constructor to default-construct a const object?
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This was considered a defect (against all versions of the standard) and it was resolved by Core Working Group (CWG) Defect 253. The new wording for the standard states in http://eel.is/c++draft/dcl.init#7
A class type T is const-default-constructible if
def...
Difference between .keystore file and .jks file
...y. Some application use a keystore file stored in $HOME/.keystore: it's usually implied that it's a JKS file, since JKS is the default keystore type in the Sun/Oracle Java security provider. Not everyone uses the .jks extension for JKS files, because it's implied as the default. I'd recommend using ...
JPA CascadeType.ALL does not delete orphans
...eType.DELETE_ORPHAN, which can be used in conjunction with JPA CascadeType.ALL.
If you don't plan to use Hibernate, you'll have to explicitly first delete the child elements and then delete the main record to avoid any orphan records.
execution sequence
fetch main row to be deleted
fetch child...
How do HTML parses work if they're not using regexp?
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Usually by using a tokeniser. The draft HTML5 specification has an extensive algorithm for handling "real world HTML".
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How to modify a global variable within a function in bash?
...alise that if you just run the function without assigning it to a variable all the global variables within it will update. Instead of returning a string array, why not just update the string array in the function then assign it to another variable after the function has finished ?
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Accessing class variables from a list comprehension in the class definition
...ing a newly created local namespace and the original global namespace. (Usually, the suite contains only function definitions.) When the class’s suite finishes execution, its execution frame is discarded but its local namespace is saved. [4] A class object is then created using the inheritance lis...
How do I check OS with a preprocessor directive?
...Unix (Linux, *BSD, Mac OS X)
See this related question on some of the pitfalls of using this check.
unix
__unix
__unix__
Mac OS X
__APPLE__
__MACH__
Both are defined; checking for either should work.
Linux
__linux__
linux Obsolete (not POSIX compliant)
__linux Obsolete (not POSIX compliant)
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