Get consistent Key error: \n

Question

当尝试运行一个包含以下用于生成文本块的代码的脚本时：

from textwrap import dedent

text = dedent("""\
   yada yada '1' ('2','3',4') 
   ('{0}', Null, '{1}',
   '{
      "Hello":"world",
    }', '1', '{2}');""").format("yada1","yada2","yada3")

我得到一致的错误KeyError '\n "Hello"
并追溯指向 .format() 的行。

当我删除 format 时一切正常，但我需要它来动态输入参数。
（最初它位于一个循环中）

Answer 1

您需要将非占位符的 { 和 } 字符加倍：

text = dedent("""\
   yada yada '1' ('2','3',4') 
   ('{0}', Null, '{1}',
   '{{
      "Hello":"world",
    }}', '1', '{2}');""").format("yada1","yada2","yada3")

否则 Python 会看到 {\n "Hello":"world",\n} 占位符，: 之前的部分是占位符名称。

来自Format String Syntax documenattion：

Format strings contain “replacement fields” surrounded by curly braces {}. Anything that is not contained in braces is considered literal text, which is copied unchanged to the output. If you need to include a brace character in the literal text, it can be escaped by doubling: {{ and }}.

（强调我的）。

Get consistent Key error: \n

Get consistent Key error: \n

python

keyerror