如何替换一个字典中作为另一个字典的键的值？答案

【问题标题】：How to replace values in one dictionary that are the keys of another?如何替换一个字典中作为另一个字典的键的值？
【发布时间】：2014-08-15 08:37:16
【问题描述】：

我有两个字典，一个存储国家名称，另一个保存相应国家的纬度、经度坐标。我想将path_dict 的值替换为另一个字典中匹配键的值。

pathcoord_dict = {"AED": [25.30000,55.43330], "EUR": [50.85000,4.35000],
                  "JPY": [35.68330,139.73330], "CNY": [39.91660,116.38330],
                  "GBP": [51.50000,-0.11670], "CAD": [45.42000, -75.67000],
                  "BRL": [-23.56660,-46.6332], "AUD": [ -33.91660,151.28330],
                  "NZD": [-36.88320,174.75000], "CHF": [46.23330,6.0667],
                  "NOK": [59.93330, 10.68330], "SEK": [59.38330 ,18.00000],
                  "SGD": [1.36670,103.75000], "HKD": [21.75000,115.00000],
                  "CNY": [39.91660,116.38330], "INR": [18.96670,72.83330],
                  "RUB": [55.75000, 37.61670], "MXN": [ 19.46670,-99.14990],
                  "TRY": [41.03330,29.00000], "AED": [25.30000,55.43330],
                  "BRL": [-23.56660,-46.6332]}

path_dict = {'AUD': [['USD'], ['JPY'], ['JPY'], ['EUR'], ['EUR'], ['INR'],
                     ['INR'], ['USD']], 'CHF': [['USD'], ['JPY'], ['JPY'],
                     ['EUR'], ['EUR'], ['INR'], ['INR'], ['USD']],
             'CNY': [['USD'], ['JPY'], ['JPY'], ['EUR'], ['EUR'], ['INR'],
                     ['INR'], ['USD']], 'TRY': [['USD'], ['JPY'], ['JPY'],
                     ['EUR'], ['EUR'], ['INR'], ['INR'], ['USD']],
             'AED': [['USD'], ['JPY'], ['JPY'], ['EUR'], ['EUR'], ['INR'],
                     ['INR'], ['USD']], 'GBP': [['USD'], ['JPY'], ['JPY'],
                     ['EUR'], ['EUR'], ['INR'], ['INR'], ['USD']],
             'NZD': [['USD'], ['JPY'], ['JPY'], ['EUR'], ['EUR'], ['INR'],
                     ['INR'], ['USD']], 'CAD': [['USD'], ['JPY'], ['JPY'],
                     ['EUR'], ['EUR'], ['INR'], ['INR'], ['USD']],
             'MXN': [['USD'], ['JPY'], ['JPY'], ['EUR'], ['EUR'], ['INR'],
                     ['INR'], ['USD']], 'NOK': [['USD'], ['JPY'], ['JPY'],
                     ['EUR'], ['EUR'], ['INR'], ['INR'], ['USD']],
             'RUB': [['USD'], ['JPY'], ['JPY'], ['EUR'], ['EUR'], ['INR'],
                     ['INR'], ['USD']], 'INR': [['USD'], ['JPY'], ['JPY'],
                     ['EUR'], ['EUR'], ['INR'], ['INR'], ['USD']],
             'JPY': [['USD'], ['JPY'], ['JPY'], ['EUR'], ['EUR'], ['INR'],
                     ['INR'], ['USD']],
             'BRL': [['USD'], ['JPY'], ['JPY'], ['EUR'], ['EUR'], ['INR'],
                     ['INR'], ['USD']],
             'EUR': [['USD'], ['JPY'], ['JPY'], ['EUR'], ['EUR'], ['INR'],
                     ['INR'], ['USD']], 'SEK': [['USD'], ['JPY'], ['JPY'],
                     ['EUR'], ['EUR'], ['INR'], ['INR'], ['USD']],
             'SGD': [['USD'], ['JPY'], ['JPY'], ['EUR'], ['EUR'], ['INR'],
                     ['INR'], ['USD']],
             'HKD': [['USD'], ['JPY'], ['JPY'], ['EUR'], ['EUR'], ['INR'],
                     ['INR'], ['USD']]}

我试图让最终结果看起来像这样

{'CHF': [[35.68330,139.73330], [50.85000,4.35000], [18.96670,72.83330], etc], ...}

【问题讨论】：

您自己尝试过的有什么想与我们分享的吗？
pathcoord_dict 不正确 - 列表 ['EUR'] 不能是 dict 中的键。
谢谢，我纠正了这个错误。
如果您不尝试自己做某事，我们为什么要这样做？
@RiggsFolly：当然是为了积分。

标签： python dictionary syntax idioms set-operations

【解决方案1】：

如果添加了pathcoord_dict 字典中缺少的"USD" 条目，您可以使用所谓的dictionary comprehension 表达式（或显示）执行类似的操作：

result = {country: [pathcoord_dict[i[0]] for i in path_dict[country]]
            for country in path_dict}

for country in result:
    print '{!r}: {}'.format(country, result[country])

输出：

'TRY': [[0.0, 0.0], [35.6833, 139.7333], [35.6833, 139.7333], [50.85, 4.35],
        [50.85, 4.35], [18.9667, 72.8333], [18.9667, 72.8333], [0.0, 0.0]]
'AUD': [[0.0, 0.0], [35.6833, 139.7333], [35.6833, 139.7333], [50.85, 4.35],
        [50.85, 4.35], [18.9667, 72.8333], [18.9667, 72.8333], [0.0, 0.0]], 
       ...

【讨论】：

【解决方案2】：

遍历 path_dict 并获取值列表中每个元素的坐标。类似于以下内容：

for k, v in path_dict.items():
  coords = [pathcoord_dict[x[0]] for x in v]
  path_dict[k] = coords

【讨论】：