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Drop data frame columns by name

...d like to remove from a data frame. I know that we can delete them individually using something like: 20 Answers ...
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Executing multi-line statements in the one-line command-line?

... The issue is not actually with the import statement, it's with anything being before the for loop. Or more specifically, anything appearing before an inlined block. For example, these all work: python -c "import sys; print 'rob'" python -c "imp...
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What's wrong with overridable method calls in constructors?

...ohibit it: There are a few more restrictions that a class must obey to allow inheritance. Constructors must not invoke overridable methods, directly or indirectly. If you violate this rule, program failure will result. The superclass constructor runs before the subclass constructor, so the overr...
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PHP - Extracting a property from an array of objects

...he question because, array_column doesn't work with an array of objects at all. Since PHP 7.0.0 is is possible: stackoverflow.com/a/23335938/655224 – algorhythm May 23 '17 at 6:36 ...
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How to make Entity Framework Data Context Readonly

...nsumer. public class ReadOnlyDataContext { private readonly DbContext _dbContext; public ReadOnlyDataContext(DbContext dbContext) { _dbContext = dbContext; } public IQueryable<TEntity> Set<TEntity>() where TEntity : class { return _dbContext.Set...
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UnicodeDecodeError: 'utf8' codec can't decode byte 0xa5 in position 0: invalid start byte

... I switched this simply by defining a different codec package in the read_csv() command: encoding = 'unicode_escape' Eg: import pandas as pd data = pd.read_csv(filename, encoding= 'unicode_escape') share | ...
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Why doesn't String switch statement support a null case?

...st by Christian Hujer has some insightful speculation about why null isn't allowed in switches (although it centers on the enum switch rather than the String switch): Under the hood, the switch statement will typically compile to a tablesswitch byte code. And the "physical" argument to switch as we...
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Storing SHA1 hash values in MySQL

...INARY(20) and CHAR(40). CREATE TABLE `binary` ( `id` int unsigned auto_increment primary key, `password` binary(20) not null ); CREATE TABLE `char` ( `id` int unsigned auto_increment primary key, `password` char(40) not null ); With million of records binary(20) takes 44.56M, whil...
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Remove Object from Array using JavaScript

... This however will remove all the occurrences found, not only the first one – Flavien Volken Jul 12 '16 at 6:49 6 ...
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How to correctly save instance state of Fragments in back stack?

... This is not related to question, onSaveInstance is not called when fragment is putted to backstack – Tadas Valaitis Jan 7 '15 at 10:14  |...