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dplyr: “Error in n(): function should not be called directly”
...ction" specification, like example below:
delay <- dplyr::summarise(by_tailnum,
count = n(),
dist = mean(distance, na.rm = TRUE),
delay = mean(arr_delay, na.rm = TRUE))
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Apache Spark: map vs mapPartitions?
...
I'm seeing the opposite -- even with very small operations, its faster to call mapPartitions and iterate than call map. I am assuming that this is just the overhead of starting the language engine that will process the map task. (I'm in R, which may have more startup...
Why are regular expressions so controversial? [closed]
...ions. And not just slow, but the performance of the regex engine can be totally unpredictable when faced with arbitrary (user-supplied) inputs.
– Pacerier
Dec 1 '15 at 21:53
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Why does `a == b or c or d` always evaluate to True?
...r is more literal minded.
if name == "Kevin" or "Jon" or "Inbar":
is logically equivalent to:
if (name == "Kevin") or ("Jon") or ("Inbar"):
Which, for user Bob, is equivalent to:
if (False) or ("Jon") or ("Inbar"):
The or operator chooses the first argument with a positive truth value:
if ("Jon")...
How do I iterate over a JSON structure? [duplicate]
...
Similarly, lodash offers _.forEach (alias _.each for underscore compatibility) to accomplish the same.
– Ville
Oct 25 '14 at 5:29
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Create timestamp variable in bash script
...cial documentation here: https://www.gnu.org/software/coreutils/manual/html_node/Time-conversion-specifiers.html#Time-conversion-specifiers
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How to export DataTable to Excel
....Select(val => $"\"{val}\"")));
lines.AddRange(valueLines);
File.WriteAllLines("excel.csv", lines);
This will write a new file excel.csv into the current working directory which is generally either where the .exe is or where you launch it from.
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Is it possible to Turn page programmatically in UIPageViewController?
Is it possible to turn page programmatically in UIPageViewController ?
17 Answers
17
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Python super() raises TypeError
...You have to design any methods that need to multiply-inherit (most notably __init__) to pass through arguments in a clean and sensible way, otherwise you'll get TypeErrors or worse debugging problems when someone tries to multiply-inherit using your class. Unless you've really designed to support MI...
Equation (expression) parser with precedence?
...ursively, for example, using your sample string,
1+11*5
to do this manually, you would have to read the 1, then see the plus and start a whole new recursive parse "session" starting with 11... and make sure to parse the 11 * 5 into its own factor, yielding a parse tree with 1 + (11 * 5).
This a...