String s = “”; String s2 = someUserInputVariale.toLowercase(); // where the user entered in “” Something like that would cause s == s2 to evaluate to false. Lots of code sill create new Strings without exposing the call to new String().
Python is not C. Unlike C, Python supports equality testing between arbitrary types. There is no ‘how’ here, strings don’t support equality testing to integers, integers don’t support equality testing to strings. So Python falls back to the default identity test behaviour, but the objects are not the same object, so the result is False. … Read more
In most languages it’s the same thing. People often do 1 == evaluated value because 1 is not an lvalue. Meaning that you can’t accidentally do an assignment. Example: if(x = 6)//bug, but no compiling error { } Instead you could force a compiling error instead of a bug: if(6 = x)//compiling error { } … Read more
They are fundamentally different. == compares by calling the __eq__ method is returns true if and only if the two references are to the same object So in comparision with say Java: is is the same as == for objects == is the same as equals for objects
Question #1: why is NaN found in a container when it’s an identical object. From the documentation: For container types such as list, tuple, set, frozenset, dict, or collections.deque, the expression x in y is equivalent to any(x is e or x == e for e in y). This is precisely what I observe with … Read more
Scala 2.7 tried to add functionality to Java [] arrays, and ran into corner cases that were problematic. Scala 2.8 has declared that Array[T] is T[], but it provides wrappers and equivalents. Try the following in 2.8 (edit/note: as of RC3, GenericArray is ArraySeq–thanks to retronym for pointing this out): import scala.collection.mutable.{GenericArray=>GArray, WrappedArray=>WArray} scala> GArray(0,1,2) … Read more
Because you are using the == (similarity) operator and PHP is coercing the string to an int. To resolve it use the === (equality) operator, which checks not only if the value is the same, but also if the data type is the same, so “123” string and 123 int won’t be considered equal.
“foo” is a string primitive. (this concept does not exist in C# or Java) new String(“foo”) is boxed string object. The === operator behaves differently on primitives and objects. When comparing primitives (of the same type), === will return true if they both have the same value. When comparing objects, === will return true only … Read more
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