Implement E401 ("multiple imports on one line") (#1326)

README.md

@@ -517,6 +517,7 @@ For more, see [pycodestyle](https://pypi.org/project/pycodestyle/2.9.1/) on PyPI
 
 | Code | Name | Message | Fix |
 | ---- | ---- | ------- | --- |
+| E401 | MultipleImportsOnOneLine | Multiple imports on one line |  |
 | E402 | ModuleImportNotAtTopOfFile | Module level import not at top of file |  |
 | E501 | LineTooLong | Line too long (89 > 88 characters) |  |
 | E711 | NoneComparison | Comparison to `None` should be `cond is None` | 🛠 |

resources/test/fixtures/pycodestyle/E40.py

@@ -0,0 +1,61 @@
+#: E401
+import os, sys
+#: Okay
+import os
+import sys
+
+from subprocess import Popen, PIPE
+
+from myclass import MyClass
+from foo.bar.yourclass import YourClass
+
+import myclass
+import foo.bar.yourclass
+#: Okay
+__all__ = ['abc']
+
+import foo
+#: Okay
+__version__ = "42"
+
+import foo
+#: Okay
+__author__ = "Simon Gomizelj"
+
+import foo
+#: Okay
+try:
+    import foo
+except ImportError:
+    pass
+else:
+    print('imported foo')
+finally:
+    print('made attempt to import foo')
+
+import bar
+#: Okay
+with warnings.catch_warnings():
+    warnings.filterwarnings("ignore", DeprecationWarning)
+    import foo
+
+import bar
+#: Okay
+if False:
+    import foo
+elif not True:
+    import bar
+else:
+    import mwahaha
+
+import bar
+#: E402
+VERSION = '1.2.3'
+
+import foo
+#: E402
+import foo
+
+a = 1
+
+import bar

src/checkers/ast.rs

@@ -628,6 +628,15 @@ where
                 }
             }
             StmtKind::Import { names } => {
+                if self.settings.enabled.contains(&CheckCode::E401) {
+                    if names.len() > 1 {
+                        self.add_check(Check::new(
+                            CheckKind::MultipleImportsOnOneLine,
+                            Range::from_located(stmt),
+                        ));
+                    }
+                }
+
                 if self.settings.enabled.contains(&CheckCode::E402) {
                     if self.seen_import_boundary && stmt.location.column() == 0 {
                         self.add_check(Check::new(

src/checks.rs

@@ -33,6 +33,7 @@ use crate::pyupgrade::types::Primitive;
 )]
 pub enum CheckCode {
     // pycodestyle errors
+    E401,
     E402,
     E501,
     E711,
@@ -644,6 +645,7 @@ pub enum CheckKind {
     IOError(String),
     LineTooLong(usize, usize),
     ModuleImportNotAtTopOfFile,
+    MultipleImportsOnOneLine,
     NoneComparison(RejectedCmpop),
     NotInTest,
     NotIsTest,
@@ -978,6 +980,7 @@ impl CheckCode {
     pub fn kind(&self) -> CheckKind {
         match self {
             // pycodestyle errors
+            CheckCode::E401 => CheckKind::MultipleImportsOnOneLine,
             CheckCode::E402 => CheckKind::ModuleImportNotAtTopOfFile,
             CheckCode::E501 => CheckKind::LineTooLong(89, 88),
             CheckCode::E711 => CheckKind::NoneComparison(RejectedCmpop::Eq),
@@ -1462,6 +1465,7 @@ impl CheckCode {
             CheckCode::DTZ007 => CheckCategory::Flake8Datetimez,
             CheckCode::DTZ011 => CheckCategory::Flake8Datetimez,
             CheckCode::DTZ012 => CheckCategory::Flake8Datetimez,
+            CheckCode::E401 => CheckCategory::Pycodestyle,
             CheckCode::E402 => CheckCategory::Pycodestyle,
             CheckCode::E501 => CheckCategory::Pycodestyle,
             CheckCode::E711 => CheckCategory::Pycodestyle,
@@ -1657,6 +1661,7 @@ impl CheckKind {
             CheckKind::IsLiteral => &CheckCode::F632,
             CheckKind::LateFutureImport => &CheckCode::F404,
             CheckKind::LineTooLong(..) => &CheckCode::E501,
+            CheckKind::MultipleImportsOnOneLine => &CheckCode::E401,
             CheckKind::ModuleImportNotAtTopOfFile => &CheckCode::E402,
             CheckKind::MultiValueRepeatedKeyLiteral => &CheckCode::F601,
             CheckKind::MultiValueRepeatedKeyVariable(_) => &CheckCode::F602,
@@ -2016,6 +2021,7 @@ impl CheckKind {
             CheckKind::ModuleImportNotAtTopOfFile => {
                 "Module level import not at top of file".to_string()
             }
+            CheckKind::MultipleImportsOnOneLine => "Multiple imports on one line".to_string(),
             CheckKind::MultiValueRepeatedKeyLiteral => {
                 "Dictionary key literal repeated".to_string()
             }

src/checks_gen.rs

@@ -179,6 +179,7 @@ pub enum CheckCodePrefix {
     E,
     E4,
     E40,
+    E401,
     E402,
     E5,
     E50,
@@ -1063,6 +1064,7 @@ impl CheckCodePrefix {
             CheckCodePrefix::DTZ011 => vec![CheckCode::DTZ011],
             CheckCodePrefix::DTZ012 => vec![CheckCode::DTZ012],
             CheckCodePrefix::E => vec![
+                CheckCode::E401,
                 CheckCode::E402,
                 CheckCode::E501,
                 CheckCode::E711,
@@ -1078,8 +1080,9 @@ impl CheckCodePrefix {
                 CheckCode::E902,
                 CheckCode::E999,
             ],
-            CheckCodePrefix::E4 => vec![CheckCode::E402],
-            CheckCodePrefix::E40 => vec![CheckCode::E402],
+            CheckCodePrefix::E4 => vec![CheckCode::E401, CheckCode::E402],
+            CheckCodePrefix::E40 => vec![CheckCode::E401, CheckCode::E402],
+            CheckCodePrefix::E401 => vec![CheckCode::E401],
             CheckCodePrefix::E402 => vec![CheckCode::E402],
             CheckCodePrefix::E5 => vec![CheckCode::E501],
             CheckCodePrefix::E50 => vec![CheckCode::E501],
@@ -2568,6 +2571,7 @@ impl CheckCodePrefix {
             CheckCodePrefix::E => SuffixLength::Zero,
             CheckCodePrefix::E4 => SuffixLength::One,
             CheckCodePrefix::E40 => SuffixLength::Two,
+            CheckCodePrefix::E401 => SuffixLength::Three,
             CheckCodePrefix::E402 => SuffixLength::Three,
             CheckCodePrefix::E5 => SuffixLength::One,
             CheckCodePrefix::E50 => SuffixLength::Two,

src/pycodestyle/mod.rs

@@ -13,24 +13,26 @@ mod tests {
     use crate::linter::test_path;
     use crate::settings;
 
-    #[test_case(CheckCode::E402, Path::new("E402.py"); "E402")]
-    #[test_case(CheckCode::E501, Path::new("E501.py"); "E501")]
-    #[test_case(CheckCode::E711, Path::new("E711.py"); "E711")]
-    #[test_case(CheckCode::E712, Path::new("E712.py"); "E712")]
-    #[test_case(CheckCode::E713, Path::new("E713.py"); "E713")]
-    #[test_case(CheckCode::E714, Path::new("E714.py"); "E714")]
-    #[test_case(CheckCode::E721, Path::new("E721.py"); "E721")]
-    #[test_case(CheckCode::E722, Path::new("E722.py"); "E722")]
-    #[test_case(CheckCode::E731, Path::new("E731.py"); "E731")]
-    #[test_case(CheckCode::E741, Path::new("E741.py"); "E741")]
-    #[test_case(CheckCode::E742, Path::new("E742.py"); "E742")]
-    #[test_case(CheckCode::E743, Path::new("E743.py"); "E743")]
-    #[test_case(CheckCode::E999, Path::new("E999.py"); "E999")]
-    #[test_case(CheckCode::W292, Path::new("W292_0.py"); "W292_0")]
-    #[test_case(CheckCode::W292, Path::new("W292_1.py"); "W292_1")]
-    #[test_case(CheckCode::W292, Path::new("W292_2.py"); "W292_2")]
-    #[test_case(CheckCode::W605, Path::new("W605_0.py"); "W605_0")]
-    #[test_case(CheckCode::W605, Path::new("W605_1.py"); "W605_1")]
+    #[test_case(CheckCode::E401, Path::new("E40.py"))]
+    #[test_case(CheckCode::E402, Path::new("E40.py"))]
+    #[test_case(CheckCode::E402, Path::new("E402.py"))]
+    #[test_case(CheckCode::E501, Path::new("E501.py"))]
+    #[test_case(CheckCode::E711, Path::new("E711.py"))]
+    #[test_case(CheckCode::E712, Path::new("E712.py"))]
+    #[test_case(CheckCode::E713, Path::new("E713.py"))]
+    #[test_case(CheckCode::E714, Path::new("E714.py"))]
+    #[test_case(CheckCode::E721, Path::new("E721.py"))]
+    #[test_case(CheckCode::E722, Path::new("E722.py"))]
+    #[test_case(CheckCode::E731, Path::new("E731.py"))]
+    #[test_case(CheckCode::E741, Path::new("E741.py"))]
+    #[test_case(CheckCode::E742, Path::new("E742.py"))]
+    #[test_case(CheckCode::E743, Path::new("E743.py"))]
+    #[test_case(CheckCode::E999, Path::new("E999.py"))]
+    #[test_case(CheckCode::W292, Path::new("W292_0.py"))]
+    #[test_case(CheckCode::W292, Path::new("W292_1.py"))]
+    #[test_case(CheckCode::W292, Path::new("W292_2.py"))]
+    #[test_case(CheckCode::W605, Path::new("W605_0.py"))]
+    #[test_case(CheckCode::W605, Path::new("W605_1.py"))]
     fn checks(check_code: CheckCode, path: &Path) -> Result<()> {
         let snapshot = format!("{}_{}", check_code.as_ref(), path.to_string_lossy());
         let mut checks = test_path(

src/pycodestyle/snapshots/ruff__pycodestyle__tests__E401_E40.py.snap

@@ -0,0 +1,13 @@
+---
+source: src/pycodestyle/mod.rs
+expression: checks
+---
+- kind: MultipleImportsOnOneLine
+  location:
+    row: 2
+    column: 0
+  end_location:
+    row: 2
+    column: 14
+  fix: ~
+

src/pycodestyle/snapshots/ruff__pycodestyle__tests__E402_E40.py.snap

@@ -0,0 +1,29 @@
+---
+source: src/pycodestyle/mod.rs
+expression: checks
+---
+- kind: ModuleImportNotAtTopOfFile
+  location:
+    row: 55
+    column: 0
+  end_location:
+    row: 55
+    column: 10
+  fix: ~
+- kind: ModuleImportNotAtTopOfFile
+  location:
+    row: 57
+    column: 0
+  end_location:
+    row: 57
+    column: 10
+  fix: ~
+- kind: ModuleImportNotAtTopOfFile
+  location:
+    row: 61
+    column: 0
+  end_location:
+    row: 61
+    column: 10
+  fix: ~
+