check number of lines, now that we're looping

Lib/test/test_import/__init__.py

@@ -999,7 +999,9 @@ class substr(str):
 """)
  popen = script_helper.spawn_python("main.py", cwd=tmp)
  stdout, stderr = popen.communicate()
- for line in stdout.splitlines():
+ lines = stdout.splitlines()
+ self.assertEqual(len(lines), 3)
+ for line in lines:
  self.assertEqual(line, b"module 'fractions' has no attribute 'Fraction'")
 
  with open(os.path.join(tmp, "main.py"), "w", encoding='utf-8') as f:
@@ -1028,7 +1030,9 @@ class substr(str):
 """)
  popen = script_helper.spawn_python("main.py", cwd=tmp)
  stdout, stderr = popen.communicate()
- for line in stdout.splitlines():
+ lines = stdout.splitlines()
+ self.assertEqual(len(lines), 3)
+ for line in lines:
  self.assertRegex(line, rb"cannot import name 'Fraction' from 'fractions' \(.*\)")
 
  # Various issues with origin
@@ -1051,7 +1055,9 @@ class substr(str):
 
  popen = script_helper.spawn_python("main.py", cwd=tmp)
  stdout, stderr = popen.communicate()
- for line in stdout.splitlines():
+ lines = stdout.splitlines()
+ self.assertEqual(len(lines), 2)
+ for line in lines:
  self.assertEqual(line, b"module 'fractions' has no attribute 'Fraction'")
 
  with open(os.path.join(tmp, "main.py"), "w", encoding='utf-8') as f:
@@ -1072,7 +1078,9 @@ class substr(str):
 """)
  popen = script_helper.spawn_python("main.py", cwd=tmp)
  stdout, stderr = popen.communicate()
- for line in stdout.splitlines():
+ lines = stdout.splitlines()
+ self.assertEqual(len(lines), 2)
+ for line in lines:
  self.assertRegex(line, rb"cannot import name 'Fraction' from 'fractions' \(.*\)")
 
  def test_script_shadowing_stdlib_sys_path_modification(self):