How to prove that parameter evaluation is "left to right" in Python?
operator-precedence, parameter-passing, python
Solution
>>> def f(x, y): pass
...
>>> f(print(1), print(2))
1
2
Problem
For example, in JavaScript we could write a program like this: ``` var a = 1; testFunction(++a, ++a, a); function testFunction(x, y, z){ document.writeln("<br />x = " + x); document.writeln("<br />y = " + y); document.writeln("<br />z = " + z); } ``` and we would get an output: ``` x = 2 y = 3 z = 3 ``` This implies that parameters are truly evaluated from left to right in JavaScript. In C we would get output ``` x = 3 y = 3 z = 3 ``` I was wondering if we could do the same in Python or is it impossible since it's a pass by value reference language? I've made a simple program but I don't think that proves anything: ``` x = 2 def f(x, y, z): print(x, y, z) f(x*2, x*2, x**2) print(x) ``` ``` 4 4 4 2 ``` Python won't let me do any new assignment within the function parameter when I call it (for example `f(x=4, x, x)` or something like this).