Question

我正在尝试打印字典值

sales_record = {
'price': 3.24,
'num_items': 4,
'person': 'xyz'}

sales_statement = 'sales_record['person'] got sales_record['num_items'] item(s) at a cost of sales_record['price']each for a total of sales_record['price']*sales_record['num_items']'

print(sales_statement)

但这只是给我一个错误

 File "<ipython-input-48-9c532ca6dcd1>", line 6
    sales_statement = 'sales_record['person'] got sales_record['num_items'] item(s) at a cost of sales_record['price']each for a total of sales_record['price']*sales_record['num_items']'

Answer 1

如果您使用的是最新版本的Python（3.6或更高版本），请将该行替换为：

sales_statement = f"{sales_record['person']} got {sales_record['num_items']} item(s) at a cost of {sales_record['price']} each for a total of {sales_record['price']*sales_record['num_items']}"

Answer 2

您需要格式化字符串。这将适用于新旧版本的Python：

  G.add_edge(149, 88)
  G.add_edge(139, 168)
  G.add_edge(215, 218)
  G.add_edge(218, 215)
  G.add_edge(429, 400)
  G.add_edge(400, 429)
  G.add_edge(207, 176) 
  G.add_edge(176, 207)
  G.add_edge(31, 45)
  G.add_edge(45, 31)
  G.add_edge(411, 381)
  G.add_edge(381, 411)
  G.add_edge(393, 335)
  G.add_edge(335, 393)
  G.add_edge(287, 317)
  G.add_edge(317, 287)
  G.add_edge(41, 77)
  ...

Answer 3

基本上是因为引号。

   Container(
          width : double.infinity,
          height : 150,
          child :  SliderTheme.of(context).copyWith(
               trackHeight :21 ,
               activeTrackColor: Colors.green,
               activeTickMarkColor: Colors.red,
               overlayColor: Colors.yellow,
               thumbColor: Colors.brown,
               inactiveTrackColor: Colors.black,
               showValueIndicator: ShowValueIndicator.always,

     child :  frs.RangeSlider(
           min: 0,
           max: 1000,
           lowerValue: 0,
           upperValue: 100,
           showValueIndicator: true,
           divisions: 20,
           onChanged: (val0,val1){

             settheState(val0);
           },
         )           

     ) )

Answer 4

您可以对全字符串使用双引号，对字典键使用单引号，以使它们之间没有混淆。在Python 3.6或更高版本中。您可以使用f字符串，并在字符串前加上字母f来将变量括在花括号中。在此之前，您将使用格式字符串方法。

sales_record = {
    'price': 3.24,
    'num_items': 4,
    'person': 'xyz'
}

sales_statement = f"{sales_record['person']} got {sales_record['num_items']} item(s) " \
                + f"at a cost of {sales_record['price']} each for a total of " \
                + f"{sales_record['price'] * sales_record['num_items']}"

print(sales_statement)

使用Python的内置方法进行字符串格式化

4 个答案: