Why this unpacking of arguments does not work?

Question

I get an error type object argument after ** must be a mapping, not tuple.

I have this code: create_character = player.Create(**generate_player.generate())

this is player.py module:

class Create(object):      def __init__(self,name,age,gender):         self.name = name         self.age = age         self.gender = gender 

this is generate_player.py module:

import prompt  def generate():      print "Name:"     name = prompt.get_name()     print "Age:"     age = prompt.get_age()     print "Gender M/F:"     gender = prompt.get_gender()      return name, age, gender 

The prompt module is just bunch of raw_inputs that return either string or integers (int for age).

Why is it returning tuples? When I run print type in generate_player module I get string, int, string for my arguments.

Answer 1

The ** syntax requires a mapping (such as a dictionary); each key-value pair in the mapping becomes a keyword argument.

Your generate() function, on the other hand, returns a tuple, not a dictionary. You can pass in a tuple as separate arguments with similar syntax, using just one asterisk:

create_character = player.Create(*generate_player.generate()) 

Alternatively, fix your generate() function to return a dictionary:

def generate():     print "Name:"     name = prompt.get_name()     print "Age:"     age = prompt.get_age()     print "Gender M/F:"     gender = prompt.get_gender()      return {'name': name, 'age': age, 'gender': gender} 

Answer 2

You just want a single asterisk:

create_character = player.Create(*generate_player.generate()) 

You're passing a sequence of arguments, for which you use one asterisk. The double-asterisk syntax is for passing a mapping, for instance to do something like this:

player.Create(**{'name': 'Richie', 'age': 21, 'gender': 'male'})