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ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.al

...al code mask = ((r["dt"] >= startdate) & (r["dt"] <= enddate)) selected = r[mask] looks correct. However, if you do want and, then instead of a and b use (a-b).any() or (a-b).all(). share | ...
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What is the easiest way to ignore a JPA field during persistence?

...uted properties, so you annotate them with @Transient to exclude them from SELECT, INSERT, UPDATE, and DELETE SQL statements. So, for basic attributes, you need to use @Transient in order to exclude a given property from being persisted. For more details about computed entity attributes, ch...
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Why do people say there is modulo bias when using a random number generator?

... Keep selecting a random is a good way to remove the bias. Update We could make the code fast if we search for an x in range divisible by n. // Assumptions // rand() in [0, RAND_MAX] // n in (0, RAND_MAX] int x; // Keep searc...
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How can you make a custom keyboard in Android?

...) { case Keyboard.KEYCODE_DELETE: CharSequence selectedText = ic.getSelectedText(0); if (TextUtils.isEmpty(selectedText)) { // no selection, so delete previous character ic.deleteSurroundingText(1, 0); ...
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Excel “External table is not in the expected format.”

...e same problem. which as resolved using these steps: 1.) Click File 2.) Select "save as" 3.) Click on drop down (Save as type) 4.) Select Excel 97-2003 Workbook 5.) Click on Save button share | ...
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How do I sort a vector of pairs based on the second element of the pair?

...),myComparison); Now you have to make the comparison based on the second selection so declare you "myComparison" as bool myComparison(const pair<int,int> &a,const pair<int,int> &b) { return a.second<b.second; } ...
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django test app error - Got an error creating the test database: permission denied to create databas

...@localhost; I originally tried to only GRANT CREATE... but then could not SELECT or DROP the created database. This essentially makes your user a superuser, so be careful. – mightypile Dec 31 '15 at 16:28 ...
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Disabling Chrome cache for website development

...ck (or hold left click) on the reload button at the top of the browser and select "Empty Cache and Hard Reload." This will go beyond "Hard Reload" to empty the cache entirely, ensuring that anything downloaded via javascript or etc. will also avoid using the cache. You don't have to mess with set...
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How to reset or change the MySQL root password?

...qld] skip-grant-tables sudo service mysql restart mysql -u root use mysql select * from mysql.user where user = 'root'; - Look at the top to determine whether the password column is called password or authentication_string UPDATE mysql.user set *password_field from above* = PASSWORD('your_new_passw...
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HTML text input allow only numeric input

...x, inputFilter) { ["input", "keydown", "keyup", "mousedown", "mouseup", "select", "contextmenu", "drop"].forEach(function(event) { textbox.addEventListener(event, function() { if (inputFilter(this.value)) { this.oldValue = this.value; this.oldSelectionStart = this.selecti...