All iterators are equality comparable. Only random access iterators are relationally comparable. Input iterators, forward iterators, and bidirectional iterators are not relationally comparable. Thus, the comparison using != is more generic and flexible than the comparison using <. There are different categories of iterators because not all ranges of elements have the same access properties. … Read more
1 == 1 == 2 // this true == 2 // becomes this 1 == 2 // which becomes this, and is false 2 > 1 == 1 // this true == 1 // becomes this 1 == 1 // which becomes this, and is true …and so on. If you’re wondering about the conversion, … Read more
It has to do with operator precedence in Python (the interpreter thinks you’re comparing True to not, since == has a higher precedence than not). You need some parentheses to clarify the order of operations: True == (not False) In general, you can’t use not on the right side of a comparison without parentheses. However, … Read more
The equality operator will attempt to make the data types the same before making the comparison. On the other hand, the identity operator requires both data types to be the same as a prerequisite. There are quite a few other posts out there similar to this questions. See: How do the PHP equality (== double … Read more
C does not understand math-like syntax, so if(1<j<=5) is not interpreted as you expect and want; it should be if (1 < j && j <= 5) or similar. As explained in other answers, the expression is evaluated as ((1 < j) <= 5) => (“true” <= 5) => “true” where “true” (boolean value) is … Read more
You are running into comparison operator chaining; 1 in () == False does not mean (1 in ()) == False. Rather, comparisons are chained and the expression really means: (1 in ()) and (() == False) Because (1 in ()) is already false, the second half of the chained expression is ignored altogether (since False … Read more
You can simply let Python tell you what bytecode is produced with the dis module: >>> import dis >>> def f(): return 1 < input(“Value:”) < 10 … >>> dis.dis(f) 1 0 LOAD_CONST 1 (1) 3 LOAD_GLOBAL 0 (input) 6 LOAD_CONST 2 (‘Value:’) 9 CALL_FUNCTION 1 12 DUP_TOP 13 ROT_THREE 14 COMPARE_OP 0 (<) 17 … Read more
I’ve never been a fan of all.equal for such things. It seems to me the tolerance works in mysterious ways sometimes. Why not just check for something greater than a tolerance less than 0.05 tol = 1e-5 (a-b) >= (0.05-tol) In general, without rounding and with just conventional logic I find straight logic better than … Read more
Empty strings are “falsy” (python 2 or python 3 reference), which means they are considered false in a Boolean context, so you can just do this: if not myString: This is the preferred way if you know that your variable is a string. If your variable could also be some other type then you should … Read more
It’s also known as the Three-Way Comparison Operator. Perl was likely the first language to use it. Some other languages that support it are Apache Groovy, PHP 7+, and C++20. The spaceship operator will return 1, 0, or −1 depending on the value of the left argument relative to the right argument. a <=> b … Read more