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What does 'predicate' mean in the context of computer science? [duplicate]
...e(arg), here Java predicate interface --> docs.oracle.com/javase/8/docs/api/java/util/function/…
– Hernán Eche
Oct 7 '15 at 18:40
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Databinding an enum property to a ComboBox in WPF
... the amount of code required by WPF to accomplish simpliest of things is really headspinning
– Konrad Morawski
Aug 29 '12 at 14:36
1
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How to call an external command?
How do you call an external command (as if I'd typed it at the Unix shell or Windows command prompt) from within a Python script?
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How to check whether a pandas DataFrame is empty?
...[8]: len(df1.columns)
Out[8]: 0
In [9]: len(df2.columns)
Out[9]: 2
Critically, while the second dataframe df2 contains no data, it is not completely empty because it returns the amount of empty columns that persist.
Why it matters
Let's add a new column to these dataframes to understand the implic...
Traits vs. interfaces
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Except that traits are not interfaces at all. Interfaces are specification that can be checked against. Traits cannot be checked against, hence they are implementation only. They are the exact opposite of interfaces. That line in the RFC is simply wrong...
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Build the full path filename in Python
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This works fine:
os.path.join(dir_name, base_filename + "." + filename_suffix)
Keep in mind that os.path.join() exists only because different operating systems use different path separator characters. It smooths over that difference so cross-platform code d...
How can I visualize per-character differences in a unified diff file?
...ight space changes):
git diff --color-words='[^[:space:]]|([[:alnum:]]|UTF_8_GUARD)+'
In general:
git diff --color-words=<re>
where <re> is a regexp defining "words" for the purpose of identifying changes.
These are less noisy in that they color the changed "words", whereas using ...
Why doesn't os.path.join() work in this case?
... the Python docs for os.path.join:
If a component is an absolute path, all previous components are thrown away and joining continues from the absolute path component.
Note on Windows, the behaviour in relation to drive letters, which seems to have changed compared to earlier Python versions:
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What happens when there's insufficient memory to throw an OutOfMemoryError?
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The JVM never really runs out of memory. It does memory computation of the heap stack in advance.
The Structure of the JVM, Chapter 3, section 3.5.2 states:
If Java virtual machine stacks can be dynamically expanded, and expansion is...
Programmatically set the initial view controller using Storyboards
How do I programmatically set the InitialViewController for a Storyboard? I want to open my storyboard to a different view depending on some condition which may vary from launch to launch.
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