“0” is a string containing the character 0, it is not the numeric value 0. The only string-type value which evaluates to false is “”. “0” is truthy. Section 9.2 of the ECMAScript 262 specification defines how different types are converted to Boolean: Argument Type Result Undefined false Null false Boolean The result equals the … Read more
Rails deliberately delegates equality checks to the identity column. If you want to know if two AR objects contain the same stuff, compare the result of calling #attributes on both.
You can use assert_frame_equals with check_names=False (so as not to check the index/columns names), which will raise if they are not equal: In [11]: from pandas.testing import assert_frame_equal In [12]: assert_frame_equal(df, expected, check_names=False) You can wrap this in a function with something like: try: assert_frame_equal(df, expected, check_names=False) return True except AssertionError: return False In more … Read more
The question is confusingly worded. Let’s break it down into many smaller questions: Why is it that one tenth plus two tenths does not always equal three tenths in floating point arithmetic? Let me give you an analogy. Suppose we have a math system where all numbers are rounded off to exactly five decimal places. … Read more
You normally use ==, it routes to equals, except that it treats nulls properly. Reference equality (rarely used) is eq.
Java only automatically interns String literals. New String objects (created using the new keyword) are not interned by default. You can use the String.intern() method to intern an existing String object. Calling intern will check the existing String pool for a matching object and return it if one exists or add it if there was … Read more
When you use <= or >= to compare two date objects, they are compared via valueOf, which is the same as getTime for Date. But when you use ==, they are two different objects of the same type, so it returns false. Added some examples: > new Date(2011, 7, 30, 0, 0, 0, 0) == … Read more
All types in .NET support the Object.Equals() method which, by default, compares two types for reference equality. However, sometimes, it also desirable to be able to compare two types for structural equality. The best example of this is arrays, which with .NET 4 now implement the IStructuralEquatable interface. This makes it possible to distinguish whether … Read more
Why not simply using the variance: var(x) == 0 If all the elements of x are equal, you will get a variance of 0. This works only for double and integers though. Edit based on the comments below: A more generic option would be to check for the length of unique elements in the vector … Read more
Well, I assume it’s because the raw binary data includes the BOM. You could always remove the BOM yourself after decoding, if you don’t want it – but you should consider whether the byte array should consider the BOM to start with. EDIT: Alternatively, you could use a StreamReader to perform the decoding. Here’s an … Read more