python - Jupyter notebook 上的多个依赖小部件(下拉菜单)

Question

我正在按照有关如何从此处处理 jupyter 笔记本上的多个依赖小部件的示例进行操作:

Dynamically changing dropdowns in IPython notebook widgets and Spyre

在该示例中，代码解决方案如下:

from IPython.html import widgets
from IPython.display import display

geo={'USA':['CHI','NYC'],'Russia':['MOW','LED']}

def print_city(city):
    print city

def select_city(country):
    cityW.options = geo[country]


scW = widgets.Dropdown(options=geo.keys())
init = scW.value
cityW = widgets.Dropdown(options=geo[init])
j = widgets.interactive(print_city, city=cityW)
i = widgets.interactive(select_city, country=scW)
display(i)
display(j)

因此，第二个下拉列表取决于第一个下拉列表的值。 这里的问题是:如果我想创建依赖于第二个下拉列表的值的第三个下拉列表怎么办？假设上面的每个城市(CHI、NYC、MOW、LED)都有一些地区，我想要第三个下拉列表，每次更新城市时都会更改。

希望问题清楚，谢谢!

Answer 1

以防万一您从未找到解决方案:我这里有一个适用于 python 3 的解决方案。我已经注释了我从原始代码更改的所有内容。希望对您有所帮助!

from IPython.html import widgets
from IPython.display import display

geo={'USA':['CHI','NYC'],'Russia':['MOW','LED']}

geo2={'CHI':['1','2'],'NYC':['3','4'],'MOW':['5','6'],'LED':['7','8']} #create dictionary with city districts

def print_city(city,district):
    print(city)
    print(district) #add in command to print district

def select_city(country):
    cityW.options = geo[country]

#add in 'select district' function that looks in the new dictionary
def select_district(city):
    districtW.options = geo2[city]

scW = widgets.Dropdown(options=geo.keys())
init = scW.value
cityW = widgets.Dropdown(options=geo[init])


init2= cityW.value #new start value for district dropdown
districtW = widgets.Dropdown(options=geo2[init2]) #define district dropdown widget

j = widgets.interactive(print_city, city=cityW, district=districtW) #define district value
i = widgets.interactive(select_city, country=scW)

k = widgets.interactive(select_district, city=cityW) #call everything together with new interactive

display(i)
display(j)