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When do we need curly braces around shell variables?
...er, the {} in ${} are useful if you want to expand the variable foo in the string
"${foo}bar"
since "$foobar" would instead expand the variable identified by foobar.
Curly braces are also unconditionally required when:
expanding array elements, as in ${array[42]}
using parameter expansion oper...
How to drop rows of Pandas DataFrame whose value in a certain column is NaN
...ilippSchwarz This error occurs if the column (EPS in the example) contains strings or other types that cannot be digested by np.isfinite(). I recommend to use pandas.notnull() that will handle this more generously.
– normanius
Apr 5 '18 at 10:02
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What is Full Text Search vs LIKE
... word
ranking—measuring the
similarity of a matching record to
the query string
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Is Enabling Double Escaping Dangerous?
...e with the uri decoded data (such as generating local filesystem URI's via string concatenation).
To disable the check do the following (from here): (see my comment below for what double escaping entails).
<system.webServer>
<security>
<requestFiltering allowDoubleEscapi...
How do I determine the size of an object in Python?
I want to know how to get size of objects like a string, integer, etc. in Python.
13 Answers
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What does “hashable” mean in Python?
...unhashable
List of immutable types:
int, float, decimal, complex, bool, string, tuple, range, frozenset, bytes
List of mutable types:
list, dict, set, bytearray, user-defined classes
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How do you access the matched groups in a JavaScript regular expression?
I want to match a portion of a string using a regular expression and then access that parenthesized substring:
22 Answers...
Last iteration of enhanced for loop in java
...n't use "" + i, by the way - you don't really want concatenation here, and StringBuilder has a perfectly good append(int) overload.)
int[] array = {1, 2, 3...};
StringBuilder builder = new StringBuilder();
for (int i : array) {
if (builder.length() != 0) {
builder.append(",");
}
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Calculate last day of month in JavaScript
...entral Standard Time)
Output differences are due to differences in the toString() implementation, not because the dates are different.
Of course, just because the browsers identified above use 0 as the last day of the previous month does not mean they will continue to do so, or that browsers not ...
mysql_fetch_array()/mysql_fetch_assoc()/mysql_fetch_row()/mysql_num_rows etc… expects parameter 1 to
... and suggestions for how to deal with them.
$username = mysql_real_escape_string($_POST['username']);
$password = $_POST['password'];
$result = mysql_query("SELECT * FROM Users WHERE UserName LIKE '$username'");
if($result === FALSE) {
die(mysql_error()); // TODO: better error handling
}
whi...