python - 为什么这不抛出 SyntaxError 而不是默默地解释错误？

Question

这两个字符串之间应该有一个逗号

foo = ['dumb'
'error']

但是如果您忘记了逗号，它只会将字符串合并在一起而不是产生语法错误。你的结果将是

['dumberror']

我花了几个小时来追踪它。为什么 Python 解释器要合并这些字符串？

Answer 1

这是一个记录在案的功能，允许在源代码中使用字符串文字进行更好的格式化。

Multiple adjacent string or bytes literals (delimited by whitespace), possibly using different quoting conventions, are allowed, and their meaning is the same as their concatenation. Thus, "hello" 'world' is equivalent to "helloworld". This feature can be used to reduce the number of backslashes needed, to split long strings conveniently across long lines, or even to add comments to parts of strings.

Source

同样值得注意的是:

Note that this feature is defined at the syntactical level, but implemented at compile time. The ‘+’ operator must be used to concatenate string expressions at run time. Also note that literal concatenation can use different quoting styles for each component (even mixing raw strings and triple quoted strings).