Question

所以我是编码的新手，这是我的第一个问题，所以如果格式不正确，我道歉。

我试图弄清楚如何组合（get_x_start）和（get_x_end）函数{其中x是赋予函数对的唯一名称}，这样每个x返回一个函数（字段）和（结束）。我尝试使用一个列表，即：

return (field,end)

但是当我尝试时，我不知道如何在（main（））中使用那些作为单独的参数，这样函数（fetch_data）可以使用来自单个x函数的两个返回参数。

我的代码如下。如果其中的任何内容不清楚，请告诉我，我会尽力澄清。感谢。

def get_data (url):  
    response = url  
    return str(response.read()) 

def fetch_data (field,data,end):  
    sen = data[data.find(field)+len(field)+3:data.find(end)-3]  
    return sen

def get_name_start (data):  
    field = "Name"  
    return field  

def get_name_end (data):  
    end = "ClosingTime"  
    return end

def get_open_start (data):  
    field = "OpeningTime"  
    return field

def get_open_end (data):  
    end = "Name"  
    return end

def get_close_start (data):  
    field = "ClosingTime"  
    return field

def get_close_end (data):  
    end = "CoLocated"  
    return end

def main ():  
    import urllib.request  
    data = get_data (urllib.request.urlopen('http://www.findfreewifi.co.za/publicjson/locationsnear?lat=-33.9568396&lng=18.45887&topX=1'))  
    print (fetch_data(get_name_start(data),data,get_name_end(data)))  
    print (fetch_data(get_open_start(data),data,get_open_end(data)))  
    print (fetch_data(get_close_start(data),data,get_close_end(data)))  

main ()

Answer 1

Here it is a function that returns a tuple

def return_ab():
    return 5, 6

Here it is a function that accepts three arguments

def test(a, b, c):
    print(a, b, c)

And here it is how you can call the test() function passing it the two parameters returned by return_ab() but unpacked

test(*return_ab(), 7) # => 5 6 7

The key point is the asterisk in front of return_ab(). It's a relatively new syntax that is very useful indeed...

Answer 2

From this post here multiple variables can be returned like this

def f(in_str):
    out_str = in_str.upper()
    return True, out_str # Creates tuple automatically

succeeded, b = f("a") # Automatic tuple unpacking

From here you can then pass your variables into the new function like:

new_f(succeeded, b)

Hope this helps

如何从函数返回两个值，然后将它们作为参数放在另一个函数的参数中作为两个参数

2 个答案: