[`perflint`] Parenthesize generator expressions (`PERF401`) (#19325)

## Summary
closes #19204 

## Test Plan
1. test case is added in dedicated file
2. locally tested the code manually

---------

Co-authored-by: Brent Westbrook <36778786+ntBre@users.noreply.github.com>
Co-authored-by: CodeMan62 <sharmahimanshu150082007@gmail.com>
This commit is contained in:
हिमांशु 2025-07-23 21:38:15 +05:30 committed by GitHub
parent ba629fe262
commit 1dcef1a011
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
4 changed files with 88 additions and 1 deletions

View File

@ -278,3 +278,15 @@ def f():
for i in src:
if lambda: 0:
dst.append(i)
def f():
i = "xyz"
result = []
for i in range(3):
result.append(x for x in [i])
def f():
i = "xyz"
result = []
for i in range(3):
result.append((x for x in [i]))

View File

@ -406,7 +406,14 @@ fn convert_to_list_extend(
};
let target_str = locator.slice(for_stmt.target.range());
let elt_str = locator.slice(to_append);
let generator_str = format!("{elt_str} {for_type} {target_str} in {for_iter_str}{if_str}");
let generator_str = if to_append
.as_generator_expr()
.is_some_and(|generator| !generator.parenthesized)
{
format!("({elt_str}) {for_type} {target_str} in {for_iter_str}{if_str}")
} else {
format!("{elt_str} {for_type} {target_str} in {for_iter_str}{if_str}")
};
let variable_name = locator.slice(binding);
let for_loop_inline_comments = comment_strings_in_range(

View File

@ -241,5 +241,27 @@ PERF401.py:280:13: PERF401 Use `list.extend` to create a transformed list
279 | if lambda: 0:
280 | dst.append(i)
| ^^^^^^^^^^^^^ PERF401
281 |
282 | def f():
|
= help: Replace for loop with list.extend
PERF401.py:286:9: PERF401 Use a list comprehension to create a transformed list
|
284 | result = []
285 | for i in range(3):
286 | result.append(x for x in [i])
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ PERF401
287 |
288 | def f():
|
= help: Replace for loop with list comprehension
PERF401.py:292:9: PERF401 Use a list comprehension to create a transformed list
|
290 | result = []
291 | for i in range(3):
292 | result.append((x for x in [i]))
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ PERF401
|
= help: Replace for loop with list comprehension

View File

@ -566,6 +566,8 @@ PERF401.py:280:13: PERF401 [*] Use `list.extend` to create a transformed list
279 | if lambda: 0:
280 | dst.append(i)
| ^^^^^^^^^^^^^ PERF401
281 |
282 | def f():
|
= help: Replace for loop with list.extend
@ -577,3 +579,47 @@ PERF401.py:280:13: PERF401 [*] Use `list.extend` to create a transformed list
279 |- if lambda: 0:
280 |- dst.append(i)
278 |+ dst.extend(i for i in src if (lambda: 0))
281 279 |
282 280 | def f():
283 281 | i = "xyz"
PERF401.py:286:9: PERF401 [*] Use a list comprehension to create a transformed list
|
284 | result = []
285 | for i in range(3):
286 | result.append(x for x in [i])
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ PERF401
287 |
288 | def f():
|
= help: Replace for loop with list comprehension
Unsafe fix
281 281 |
282 282 | def f():
283 283 | i = "xyz"
284 |- result = []
285 |- for i in range(3):
286 |- result.append(x for x in [i])
284 |+ result = [(x for x in [i]) for i in range(3)]
287 285 |
288 286 | def f():
289 287 | i = "xyz"
PERF401.py:292:9: PERF401 [*] Use a list comprehension to create a transformed list
|
290 | result = []
291 | for i in range(3):
292 | result.append((x for x in [i]))
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ PERF401
|
= help: Replace for loop with list comprehension
Unsafe fix
287 287 |
288 288 | def f():
289 289 | i = "xyz"
290 |- result = []
291 |- for i in range(3):
292 |- result.append((x for x in [i]))
290 |+ result = [(x for x in [i]) for i in range(3)]