unnecessary-generator-set (C401) （不必要的生成器集合 (C401)）

Derived from the flake8-comprehensions linter. （源自 flake8-comprehensions linter。）

修复总是可用的。

作用

Checks for unnecessary generators that can be rewritten as set comprehensions (or with set() directly). （检查可以重写为集合推导式（或直接使用set()）的不必要的生成器。）

为什么这不好？

It is unnecessary to use set around a generator expression, since there are equivalent comprehensions for these types. Using a comprehension is clearer and more idiomatic. （围绕生成器表达式使用set是不必要的，因为对于这些类型存在等效的推导式。使用推导式更清晰也更符合语言习惯。）

Further, if the comprehension can be removed entirely, as in the case of set(x for x in foo), it's better to use set(foo) directly, since it's even more direct. （此外，如果可以完全删除推导式，例如在set(x for x in foo)的情况下，最好直接使用set(foo)，因为它更直接。）

示例

set(f(x) for x in foo)
set(x for x in foo)
set((x for x in foo))

建议改为

{f(x) for x in foo}
set(foo)
set(foo)

修复安全性

This rule's fix is marked as unsafe, as it may occasionally drop comments when rewriting the call. In most cases, though, comments will be preserved. （此规则的修复被标记为不安全，因为它在重写调用时有时会删除注释。但在大多数情况下，注释将被保留。）