1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
|
from dataclasses import dataclass
from mypy.nodes import CallExpr, MemberExpr, NameExpr, StrExpr
from refurb.error import Error
@dataclass
class ErrorInfo(Error):
"""
Certain expressions which are passed to f-strings are redundant because
the f-string itself is capable of formatting it. For example:
Bad:
```
print(f"{bin(1337)}")
print(f"{ascii(input())}")
print(f"{str(123)}")
```
Good:
```
print(f"{1337:#b}")
print(f"{input()!a}")
print(f"{123}")
```
"""
name = "use-fstring-format"
code = 119
categories = ("builtin", "fstring")
CONVERSIONS = {
"builtins.str": "x",
"builtins.repr": "x!r",
"builtins.ascii": "x!a",
"builtins.bin": "x:#b",
"builtins.oct": "x:#o",
"builtins.hex": "x:#x",
"builtins.chr": "x:c",
"builtins.format": "x",
}
def check(node: CallExpr, errors: list[Error]) -> None:
match node:
case CallExpr(
callee=MemberExpr(expr=StrExpr(value="{:{}}"), name="format"),
args=[inner, _],
):
match inner:
case CallExpr(
callee=NameExpr(fullname=fullname) as func,
args=[_],
) if fullname in CONVERSIONS:
func_name = f"{{{func.name}(x)}}"
conversion = f"{{{CONVERSIONS[fullname or '']}}}" # noqa: FURB143, E501
errors.append(
ErrorInfo.from_node(node, f"Replace `{func_name}` with `{conversion}`")
)
|
