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How to print a groupby object
...like a bug to me. I created an issue.
But a groupby operation doesn't actually return a DataFrame sorted by group. The .head() method is a little misleading here -- it's just a convenience feature to let you re-examine the object (in this case, df) that you grouped. The result of groupby is separat...
Insert, on duplicate update in PostgreSQL?
...it would be much slower, because each upsert would be its' own individual call into the database.
– baash05
Mar 1 '12 at 0:27
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Why does HTML5 form-validation allow emails without a dot?
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I wonder when the last time someone actually sent an email to localhost!
– Matthew Lock
May 19 '17 at 3:14
2
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How to quickly check if folder is empty (.NET)?
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There is a new feature in Directory and DirectoryInfo in .NET 4 that allows them to return an IEnumerable instead of an array, and start returning results before reading all the directory contents.
What's New in the BCL in .NET 4 Beta 1
Directory.EnumerateFileSystemEntries method overloads
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How do I use extern to share variables between source files?
...ler is informed that a
variable exists (and this is its type); it does not allocate the
storage for the variable at that point.
A variable is defined when the compiler allocates the storage for
the variable.
You may declare a variable multiple times (though once is sufficient);
you may only defin...
Creating C formatted strings (not printing them)
...ee snprintf for a safer version).
A terminating null character is automatically appended after the
content.
After the format parameter, the function expects at least as many
additional arguments as needed for format.
Parameters:
str
Pointer to a buffer where the resulting C-string is stored. The ...
Have a reloadData for a UITableView animate when changing
...the modes I have a different number of sections and cells per section. Ideally, it would do some cool animation when the table grows or shrinks.
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Load multiple packages at once
...t retyping the require command over and over? I've tried three approaches all of which crash and burn.
10 Answers
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How do I print the type of a variable in Rust?
...r
|
= note: expected type `()`
found type `{float}`
Or call an invalid method:
let mut my_number = 32.90;
my_number.what_is_this();
error[E0599]: no method named `what_is_this` found for type `{float}` in the current scope
--> src/main.rs:3:15
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3 | my_number.what_is_...
Swift equivalent for MIN and MAX macros
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With Swift 5, max(_:_:) and min(_:_:) are part of the Global Numeric Functions. max(_:_:) has the following declaration:
func max<T>(_ x: T, _ y: T) -> T where T : Comparable
You can use it like this with Ints:
let maxInt = max(5,...