Recursive code returns None [duplicate]
You probably want a return on the last line: return isIn(char, aStr) Without it, the function simply returns None when it terminates without seeing a return.
You probably want a return on the last line: return isIn(char, aStr) Without it, the function simply returns None when it terminates without seeing a return.
You can use dict.get() value = d.get(key) which will return None if key is not in d. You can also provide a different default value that will be returned instead of None: value = d.get(key, “empty”)
Summary: Use is when you want to check against an object’s identity (e.g. checking to see if var is None). Use == when you want to check equality (e.g. Is var equal to 3?). Explanation: You can have custom classes where my_var == None will return True e.g: class Negator(object): def __eq__(self,other): return not other … Read more
append is a mutating (destructive) operation (it modifies the list in place instead of of returning a new list). The idiomatic way to do the non-destructive equivalent of append would be >>> l = [1,2,3] >>> l + [4] [1,2,3,4] >>> l [1,2,3] to answer your question, my guess is that if append returned the … Read more