Python 为什么这种解压参数不起作用？
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Why this unpacking of arguments does not work?
提问by user3056783
I get an error type object argument after ** must be a mapping, not tuple.
我收到一个错误type object argument after ** must be a mapping, not tuple。
I have this code:
create_character = player.Create(**generate_player.generate())
我有这个代码：
create_character = player.Create(**generate_player.generate())
this is player.pymodule:
这是player.py模块：
class Create(object):
def __init__(self,name,age,gender):
self.name = name
self.age = age
self.gender = gender
this is generate_player.pymodule:
这是generate_player.py模块：
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 promptmodule is just bunch of raw_inputs that return either string or integers (int for age).
该prompt模块只是一堆raw_input返回字符串或整数（int for age）的s 。
Why is it returning tuples? When I run print typein generate_playermodule I get string, int, string for my arguments.
为什么它返回元组？当我print type在generate_player模块中运行时，我的参数得到 string、int、string。
采纳答案by Martijn Pieters
The **syntax requires a mapping(such as a dictionary); each key-value pair in the mapping becomes a keyword argument.
的**语法要求一个映射（如字典）; 映射中的每个键值对都成为关键字参数。
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 oneasterisk:
generate()另一方面，您的函数返回一个元组，而不是一个字典。您可以将元组作为具有类似语法的单独参数传入，只需使用一个星号：
create_character = player.Create(*generate_player.generate())
Alternatively, fix your generate()function to return a dictionary:
或者，修复您的generate()函数以返回字典：
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}
回答by RichieHindle
You just want a single asterisk:
你只需要一个星号：
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:
您正在传递一系列参数，为此您使用一个星号。双星号语法用于传递映射，例如执行以下操作：
player.Create(**{'name': 'Richie', 'age': 21, 'gender': 'male'})
