From ad7da4f049aa246fef5855155163d3d796d613c8 Mon Sep 17 00:00:00 2001
From: Akash Kwatra <akashkw@gmail.com>
Date: Mon, 28 Feb 2022 12:56:43 -0800
Subject: [PATCH 01/10] deprecate LoggerCollection

---
 pytorch_lightning/trainer/trainer.py    |  9 +++++----
 tests/deprecated_api/test_remove_1-8.py | 21 +++++++++++++++++++++
 2 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/pytorch_lightning/trainer/trainer.py b/pytorch_lightning/trainer/trainer.py
index 46e9aeb368c90..cac1603300f5d 100644
--- a/pytorch_lightning/trainer/trainer.py
+++ b/pytorch_lightning/trainer/trainer.py
@@ -2599,10 +2599,11 @@ def logger(self) -> Optional[LightningLoggerBase]:
         if len(self.loggers) == 1:
             return self.loggers[0]
         else:
-            rank_zero_warn(
-                "Using trainer.logger when Trainer is configured to use multiple loggers."
-                " This behavior will change in v1.8 when LoggerCollection is removed, and"
-                " trainer.logger will return the first logger in trainer.loggers"
+            rank_zero_deprecation(
+                "Using `trainer.logger` when Trainer is configured to use multiple loggers."
+                " `LoggerCollection` is deprecated in v1.6 and will be removed in v1.8."
+                " This behavior will change in v1.8 such that `trainer.logger` will return the first"
+                " logger in `trainer.loggers`."
             )
             return LoggerCollection(self.loggers)
 
diff --git a/tests/deprecated_api/test_remove_1-8.py b/tests/deprecated_api/test_remove_1-8.py
index 09e82ddbe3ae3..d265d58d7a6af 100644
--- a/tests/deprecated_api/test_remove_1-8.py
+++ b/tests/deprecated_api/test_remove_1-8.py
@@ -652,3 +652,24 @@ def _get_python_cprofile_total_duration(profile):
     recorded_total_duration = _get_python_cprofile_total_duration(advanced_profiler.profiled_actions[action])
     expected_total_duration = np.sum(expected)
     np.testing.assert_allclose(recorded_total_duration, expected_total_duration, rtol=0.2)
+
+
+def test_v1_8_0_logger_collection(tmpdir):
+    logger1 = CSVLogger(tmpdir)
+    logger2 = CSVLogger(tmpdir)
+
+    trainer1 = Trainer(logger=logger1)
+    trainer2 = Trainer(logger=[logger1, logger2])
+
+    # Should have no deprecation warning
+    trainer1.logger
+    trainer1.loggers
+    trainer2.loggers
+
+    with pytest.deprecated_call(
+        match="Using `trainer.logger` when Trainer is configured to use multiple loggers."
+        " `LoggerCollection` is deprecated in v1.6 and will be removed in v1.8."
+        " This behavior will change in v1.8 such that `trainer.logger` will return the first"
+        " logger in `trainer.loggers`."
+    ):
+        trainer1.logger

From b519a1615d790d8fc7fc939cab0baf6d2631a31b Mon Sep 17 00:00:00 2001
From: Akash Kwatra <akashkw@gmail.com>
Date: Mon, 28 Feb 2022 13:05:25 -0800
Subject: [PATCH 02/10] update changelog

---
 CHANGELOG.md                            | 3 +++
 pytorch_lightning/trainer/trainer.py    | 2 +-
 tests/deprecated_api/test_remove_1-8.py | 2 +-
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9606b7d653aed..adb68840f8bae 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -445,6 +445,9 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - Deprecated `BaseProfiler.profile_iterable` ([#12102](https://github.com/PyTorchLightning/pytorch-lightning/pull/12102))
 
 
+- Deprecated `LoggerCollection` in favor of `trainer.loggers` ([#12147](https://github.com/PyTorchLightning/pytorch-lightning/pull/12147))
+
+
 ### Removed
 
 - Removed deprecated parameter `method` in `pytorch_lightning.utilities.model_helpers.is_overridden` ([#10507](https://github.com/PyTorchLightning/pytorch-lightning/pull/10507))
diff --git a/pytorch_lightning/trainer/trainer.py b/pytorch_lightning/trainer/trainer.py
index cac1603300f5d..a6ab189f08a0f 100644
--- a/pytorch_lightning/trainer/trainer.py
+++ b/pytorch_lightning/trainer/trainer.py
@@ -2601,7 +2601,7 @@ def logger(self) -> Optional[LightningLoggerBase]:
         else:
             rank_zero_deprecation(
                 "Using `trainer.logger` when Trainer is configured to use multiple loggers."
-                " `LoggerCollection` is deprecated in v1.6 and will be removed in v1.8."
+                " `LoggerCollection` is deprecated in v1.6 in favor of `trainer.loggers` and will be removed in v1.8."
                 " This behavior will change in v1.8 such that `trainer.logger` will return the first"
                 " logger in `trainer.loggers`."
             )
diff --git a/tests/deprecated_api/test_remove_1-8.py b/tests/deprecated_api/test_remove_1-8.py
index d265d58d7a6af..1f9cebeb6d04a 100644
--- a/tests/deprecated_api/test_remove_1-8.py
+++ b/tests/deprecated_api/test_remove_1-8.py
@@ -668,7 +668,7 @@ def test_v1_8_0_logger_collection(tmpdir):
 
     with pytest.deprecated_call(
         match="Using `trainer.logger` when Trainer is configured to use multiple loggers."
-        " `LoggerCollection` is deprecated in v1.6 and will be removed in v1.8."
+        " `LoggerCollection` is deprecated in v1.6 in favor of `trainer.loggers` and will be removed in v1.8."
         " This behavior will change in v1.8 such that `trainer.logger` will return the first"
         " logger in `trainer.loggers`."
     ):

From a6bcbf77fbfacf2bc3a40e10992e6dff75594cc0 Mon Sep 17 00:00:00 2001
From: Akash Kwatra <akashkw@gmail.com>
Date: Mon, 28 Feb 2022 13:36:52 -0800
Subject: [PATCH 03/10] fix unit tests

---
 tests/deprecated_api/test_remove_1-8.py  |  2 +-
 tests/profiler/test_profiler.py          | 14 +++++++-------
 tests/trainer/properties/test_log_dir.py |  7 +++----
 tests/trainer/properties/test_loggers.py | 12 ++++++++++--
 4 files changed, 21 insertions(+), 14 deletions(-)

diff --git a/tests/deprecated_api/test_remove_1-8.py b/tests/deprecated_api/test_remove_1-8.py
index 1f9cebeb6d04a..4032050edd719 100644
--- a/tests/deprecated_api/test_remove_1-8.py
+++ b/tests/deprecated_api/test_remove_1-8.py
@@ -672,4 +672,4 @@ def test_v1_8_0_logger_collection(tmpdir):
         " This behavior will change in v1.8 such that `trainer.logger` will return the first"
         " logger in `trainer.loggers`."
     ):
-        trainer1.logger
+        trainer2.logger
diff --git a/tests/profiler/test_profiler.py b/tests/profiler/test_profiler.py
index 161c9e6e35670..24f6c70e72b88 100644
--- a/tests/profiler/test_profiler.py
+++ b/tests/profiler/test_profiler.py
@@ -24,7 +24,7 @@
 
 from pytorch_lightning import Callback, Trainer
 from pytorch_lightning.callbacks import EarlyStopping, StochasticWeightAveraging
-from pytorch_lightning.loggers import CSVLogger, LoggerCollection, TensorBoardLogger
+from pytorch_lightning.loggers import CSVLogger, TensorBoardLogger
 from pytorch_lightning.profiler import AdvancedProfiler, PassThroughProfiler, PyTorchProfiler, SimpleProfiler
 from pytorch_lightning.profiler.pytorch import RegisterRecordFunction, warning_cache
 from pytorch_lightning.utilities.exceptions import MisconfigurationException
@@ -450,9 +450,9 @@ def test_pytorch_profiler_nested(tmpdir):
     assert events_name == expected, (events_name, torch.__version__, platform.system())
 
 
-def test_pytorch_profiler_logger_collection(tmpdir):
-    """Tests whether the PyTorch profiler is able to write its trace locally when the Trainer's logger is an
-    instance of LoggerCollection.
+def test_pytorch_profiler_multiple_loggers(tmpdir):
+    """Tests whether the PyTorch profiler is able to write its trace locally when the Trainer is configured with
+    multiple loggers.
 
     See issue #8157.
     """
@@ -466,9 +466,9 @@ def look_for_trace(trace_dir):
 
     model = BoringModel()
     # Wrap the logger in a list so it becomes a LoggerCollection
-    logger = [TensorBoardLogger(save_dir=tmpdir), CSVLogger(tmpdir)]
-    trainer = Trainer(default_root_dir=tmpdir, profiler="pytorch", logger=logger, limit_train_batches=5, max_epochs=1)
-    assert isinstance(trainer.logger, LoggerCollection)
+    loggers = [TensorBoardLogger(save_dir=tmpdir), CSVLogger(tmpdir)]
+    trainer = Trainer(default_root_dir=tmpdir, profiler="pytorch", logger=loggers, limit_train_batches=5, max_epochs=1)
+    assert len(trainer.loggers) == 2
     trainer.fit(model)
     assert look_for_trace(tmpdir)
 
diff --git a/tests/trainer/properties/test_log_dir.py b/tests/trainer/properties/test_log_dir.py
index 6777ec8183737..db2f862f82e7b 100644
--- a/tests/trainer/properties/test_log_dir.py
+++ b/tests/trainer/properties/test_log_dir.py
@@ -15,7 +15,7 @@
 
 from pytorch_lightning import Trainer
 from pytorch_lightning.callbacks import ModelCheckpoint
-from pytorch_lightning.loggers import CSVLogger, LoggerCollection, TensorBoardLogger
+from pytorch_lightning.loggers import CSVLogger, TensorBoardLogger
 from tests.helpers.boring_model import BoringModel
 
 
@@ -109,8 +109,8 @@ def test_logdir_custom_logger(tmpdir):
     assert trainer.log_dir == expected
 
 
-def test_logdir_logger_collection(tmpdir):
-    """Tests that the logdir equals the default_root_dir when the logger is a LoggerCollection."""
+def test_logdir_multiple_loggers(tmpdir):
+    """Tests that the logdir equals the default_root_dir when trainer has multiple loggers."""
     default_root_dir = tmpdir / "default_root_dir"
     save_dir = tmpdir / "save_dir"
     model = TestModel(default_root_dir)
@@ -119,7 +119,6 @@ def test_logdir_logger_collection(tmpdir):
         max_steps=2,
         logger=[TensorBoardLogger(save_dir=save_dir, name="custom_logs"), CSVLogger(tmpdir)],
     )
-    assert isinstance(trainer.logger, LoggerCollection)
     assert trainer.log_dir == default_root_dir
 
     trainer.fit(model)
diff --git a/tests/trainer/properties/test_loggers.py b/tests/trainer/properties/test_loggers.py
index d3db78986f361..f1075f2dc1c90 100644
--- a/tests/trainer/properties/test_loggers.py
+++ b/tests/trainer/properties/test_loggers.py
@@ -12,6 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import pytest
+
 from pytorch_lightning import Trainer
 from pytorch_lightning.loggers import LoggerCollection, TensorBoardLogger
 from tests.loggers.test_base import CustomLogger
@@ -52,6 +54,10 @@ def test_trainer_loggers_setters():
     logger2 = CustomLogger()
     logger_collection = LoggerCollection([logger1, logger2])
     logger_collection_2 = LoggerCollection([logger2])
+    logger_collection_dep = "Using `trainer.logger` when Trainer is configured to use multiple loggers."
+    " `LoggerCollection` is deprecated in v1.6 in favor of `trainer.loggers` and will be removed in v1.8."
+    " This behavior will change in v1.8 such that `trainer.logger` will return the first"
+    " logger in `trainer.loggers`."
 
     trainer = Trainer()
     assert type(trainer.logger) == TensorBoardLogger
@@ -63,7 +69,8 @@ def test_trainer_loggers_setters():
     assert trainer.loggers == [logger1]
 
     trainer.logger = logger_collection
-    assert trainer.logger._logger_iterable == logger_collection._logger_iterable
+    with pytest.deprecated_call(match=logger_collection_dep):
+        assert trainer.logger._logger_iterable == logger_collection._logger_iterable
     assert trainer.loggers == [logger1, logger2]
 
     # LoggerCollection of size 1 should result in trainer.logger becoming the contained logger.
@@ -78,7 +85,8 @@ def test_trainer_loggers_setters():
     # Test setters for trainer.loggers
     trainer.loggers = [logger1, logger2]
     assert trainer.loggers == [logger1, logger2]
-    assert trainer.logger._logger_iterable == logger_collection._logger_iterable
+    with pytest.deprecated_call(match=logger_collection_dep):
+        assert trainer.logger._logger_iterable == logger_collection._logger_iterable
 
     trainer.loggers = [logger1]
     assert trainer.loggers == [logger1]

From 2efd7776ad9c32c6635f031d930afa92743842df Mon Sep 17 00:00:00 2001
From: Akash Kwatra <akashkw@gmail.com>
Date: Mon, 28 Feb 2022 14:58:35 -0800
Subject: [PATCH 04/10] Split deprecation message

---
 pytorch_lightning/loggers/base.py        |  6 ++++++
 pytorch_lightning/trainer/trainer.py     |  1 -
 tests/deprecated_api/test_remove_1-8.py  | 14 +++++++-------
 tests/trainer/properties/test_loggers.py | 11 +++++------
 4 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/pytorch_lightning/loggers/base.py b/pytorch_lightning/loggers/base.py
index f0a8ba13dbdcd..dae253e393433 100644
--- a/pytorch_lightning/loggers/base.py
+++ b/pytorch_lightning/loggers/base.py
@@ -221,6 +221,9 @@ def version(self) -> Union[int, str]:
 class LoggerCollection(LightningLoggerBase):
     """The :class:`LoggerCollection` class is used to iterate all logging actions over the given `logger_iterable`.
 
+    .. deprecated:: v1.6
+        `LoggerCollection` is deprecated in v1.6 in favor of `trainer.loggers` and will be removed in v1.8.
+
     Args:
         logger_iterable: An iterable collection of loggers
     """
@@ -228,6 +231,9 @@ class LoggerCollection(LightningLoggerBase):
     def __init__(self, logger_iterable: Iterable[LightningLoggerBase]):
         super().__init__()
         self._logger_iterable = logger_iterable
+        rank_zero_deprecation(
+            "`LoggerCollection` is deprecated in v1.6 in favor of `trainer.loggers` and will be removed in v1.8."
+        )
 
     def __getitem__(self, index: int) -> LightningLoggerBase:
         return list(self._logger_iterable)[index]
diff --git a/pytorch_lightning/trainer/trainer.py b/pytorch_lightning/trainer/trainer.py
index a6ab189f08a0f..355c75b87d562 100644
--- a/pytorch_lightning/trainer/trainer.py
+++ b/pytorch_lightning/trainer/trainer.py
@@ -2601,7 +2601,6 @@ def logger(self) -> Optional[LightningLoggerBase]:
         else:
             rank_zero_deprecation(
                 "Using `trainer.logger` when Trainer is configured to use multiple loggers."
-                " `LoggerCollection` is deprecated in v1.6 in favor of `trainer.loggers` and will be removed in v1.8."
                 " This behavior will change in v1.8 such that `trainer.logger` will return the first"
                 " logger in `trainer.loggers`."
             )
diff --git a/tests/deprecated_api/test_remove_1-8.py b/tests/deprecated_api/test_remove_1-8.py
index 4032050edd719..68c03463036a0 100644
--- a/tests/deprecated_api/test_remove_1-8.py
+++ b/tests/deprecated_api/test_remove_1-8.py
@@ -21,7 +21,7 @@
 from torch import optim
 
 from pytorch_lightning import Callback, Trainer
-from pytorch_lightning.loggers import CSVLogger, LightningLoggerBase
+from pytorch_lightning.loggers import CSVLogger, LightningLoggerBase, LoggerCollection
 from pytorch_lightning.plugins.training_type.ddp import DDPPlugin
 from pytorch_lightning.plugins.training_type.ddp2 import DDP2Plugin
 from pytorch_lightning.plugins.training_type.ddp_spawn import DDPSpawnPlugin
@@ -666,10 +666,10 @@ def test_v1_8_0_logger_collection(tmpdir):
     trainer1.loggers
     trainer2.loggers
 
-    with pytest.deprecated_call(
-        match="Using `trainer.logger` when Trainer is configured to use multiple loggers."
-        " `LoggerCollection` is deprecated in v1.6 in favor of `trainer.loggers` and will be removed in v1.8."
-        " This behavior will change in v1.8 such that `trainer.logger` will return the first"
-        " logger in `trainer.loggers`."
-    ):
+    with pytest.deprecated_call(match="`LoggerCollection` is deprecated in v1.6"):
+        trainer2.logger
+
+    with pytest.deprecated_call(match="Using `trainer.logger` when Trainer is configured to use multiple loggers."):
         trainer2.logger
+    with pytest.deprecated_call(match="`LoggerCollection` is deprecated in v1.6"):
+        LoggerCollection([logger1, logger2])
diff --git a/tests/trainer/properties/test_loggers.py b/tests/trainer/properties/test_loggers.py
index f1075f2dc1c90..b24b3646832a5 100644
--- a/tests/trainer/properties/test_loggers.py
+++ b/tests/trainer/properties/test_loggers.py
@@ -52,12 +52,11 @@ def test_trainer_loggers_setters():
     """Test the behavior of setters for trainer.logger and trainer.loggers."""
     logger1 = CustomLogger()
     logger2 = CustomLogger()
-    logger_collection = LoggerCollection([logger1, logger2])
-    logger_collection_2 = LoggerCollection([logger2])
-    logger_collection_dep = "Using `trainer.logger` when Trainer is configured to use multiple loggers."
-    " `LoggerCollection` is deprecated in v1.6 in favor of `trainer.loggers` and will be removed in v1.8."
-    " This behavior will change in v1.8 such that `trainer.logger` will return the first"
-    " logger in `trainer.loggers`."
+    logger_collection_dep = "`LoggerCollection` is deprecated in v1.6"
+    with pytest.deprecated_call(match=logger_collection_dep):
+        logger_collection = LoggerCollection([logger1, logger2])
+    with pytest.deprecated_call(match=logger_collection_dep):
+        logger_collection_2 = LoggerCollection([logger2])
 
     trainer = Trainer()
     assert type(trainer.logger) == TensorBoardLogger

From 6b26948b25915b59f3c0ff9f500db82b237169eb Mon Sep 17 00:00:00 2001
From: Akash Kwatra <akashkw@gmail.com>
Date: Mon, 28 Feb 2022 15:47:11 -0800
Subject: [PATCH 05/10] fix unit tests and change dep to warning

---
 pytorch_lightning/trainer/trainer.py     |  2 +-
 tests/deprecated_api/test_remove_1-8.py  |  2 --
 tests/loggers/test_base.py               | 15 ++++++++++-----
 tests/profiler/test_profiler.py          |  1 -
 tests/trainer/properties/test_loggers.py |  9 ++++-----
 5 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/pytorch_lightning/trainer/trainer.py b/pytorch_lightning/trainer/trainer.py
index 355c75b87d562..ce9d3ae68bd84 100644
--- a/pytorch_lightning/trainer/trainer.py
+++ b/pytorch_lightning/trainer/trainer.py
@@ -2599,7 +2599,7 @@ def logger(self) -> Optional[LightningLoggerBase]:
         if len(self.loggers) == 1:
             return self.loggers[0]
         else:
-            rank_zero_deprecation(
+            rank_zero_warn(
                 "Using `trainer.logger` when Trainer is configured to use multiple loggers."
                 " This behavior will change in v1.8 such that `trainer.logger` will return the first"
                 " logger in `trainer.loggers`."
diff --git a/tests/deprecated_api/test_remove_1-8.py b/tests/deprecated_api/test_remove_1-8.py
index 68c03463036a0..0e8639a9d111f 100644
--- a/tests/deprecated_api/test_remove_1-8.py
+++ b/tests/deprecated_api/test_remove_1-8.py
@@ -669,7 +669,5 @@ def test_v1_8_0_logger_collection(tmpdir):
     with pytest.deprecated_call(match="`LoggerCollection` is deprecated in v1.6"):
         trainer2.logger
 
-    with pytest.deprecated_call(match="Using `trainer.logger` when Trainer is configured to use multiple loggers."):
-        trainer2.logger
     with pytest.deprecated_call(match="`LoggerCollection` is deprecated in v1.6"):
         LoggerCollection([logger1, logger2])
diff --git a/tests/loggers/test_base.py b/tests/loggers/test_base.py
index cd7eec14eec77..ff93f9933d74b 100644
--- a/tests/loggers/test_base.py
+++ b/tests/loggers/test_base.py
@@ -34,7 +34,8 @@ def test_logger_collection():
     mock1 = MagicMock()
     mock2 = MagicMock()
 
-    logger = LoggerCollection([mock1, mock2])
+    with pytest.deprecated_call(match="`LoggerCollection` is deprecated in v1.6"):
+        logger = LoggerCollection([mock1, mock2])
 
     assert logger[0] == mock1
     assert logger[1] == mock2
@@ -62,14 +63,16 @@ def test_logger_collection_unique_names():
     logger1 = CustomLogger(name=unique_name)
     logger2 = CustomLogger(name=unique_name)
 
-    logger = LoggerCollection([logger1, logger2])
+    with pytest.deprecated_call(match="`LoggerCollection` is deprecated in v1.6"):
+        logger = LoggerCollection([logger1, logger2])
 
     assert logger.name == unique_name
 
 
 def test_logger_collection_names_order():
     loggers = [CustomLogger(name=n) for n in ("name1", "name2", "name1", "name3")]
-    logger = LoggerCollection(loggers)
+    with pytest.deprecated_call(match="`LoggerCollection` is deprecated in v1.6"):
+        logger = LoggerCollection(loggers)
     assert logger.name == f"{loggers[0].name}_{loggers[1].name}_{loggers[3].name}"
 
 
@@ -78,14 +81,16 @@ def test_logger_collection_unique_versions():
     logger1 = CustomLogger(version=unique_version)
     logger2 = CustomLogger(version=unique_version)
 
-    logger = LoggerCollection([logger1, logger2])
+    with pytest.deprecated_call(match="`LoggerCollection` is deprecated in v1.6"):
+        logger = LoggerCollection([logger1, logger2])
 
     assert logger.version == unique_version
 
 
 def test_logger_collection_versions_order():
     loggers = [CustomLogger(version=v) for v in ("1", "2", "1", "3")]
-    logger = LoggerCollection(loggers)
+    with pytest.deprecated_call(match="`LoggerCollection` is deprecated in v1.6"):
+        logger = LoggerCollection(loggers)
     assert logger.version == f"{loggers[0].version}_{loggers[1].version}_{loggers[3].version}"
 
 
diff --git a/tests/profiler/test_profiler.py b/tests/profiler/test_profiler.py
index 24f6c70e72b88..2971ba7bc2c19 100644
--- a/tests/profiler/test_profiler.py
+++ b/tests/profiler/test_profiler.py
@@ -465,7 +465,6 @@ def look_for_trace(trace_dir):
     assert not look_for_trace(tmpdir)
 
     model = BoringModel()
-    # Wrap the logger in a list so it becomes a LoggerCollection
     loggers = [TensorBoardLogger(save_dir=tmpdir), CSVLogger(tmpdir)]
     trainer = Trainer(default_root_dir=tmpdir, profiler="pytorch", logger=loggers, limit_train_batches=5, max_epochs=1)
     assert len(trainer.loggers) == 2
diff --git a/tests/trainer/properties/test_loggers.py b/tests/trainer/properties/test_loggers.py
index b24b3646832a5..3b3ffeea44310 100644
--- a/tests/trainer/properties/test_loggers.py
+++ b/tests/trainer/properties/test_loggers.py
@@ -52,10 +52,9 @@ def test_trainer_loggers_setters():
     """Test the behavior of setters for trainer.logger and trainer.loggers."""
     logger1 = CustomLogger()
     logger2 = CustomLogger()
-    logger_collection_dep = "`LoggerCollection` is deprecated in v1.6"
-    with pytest.deprecated_call(match=logger_collection_dep):
+    with pytest.deprecated_call(match="`LoggerCollection` is deprecated in v1.6"):
         logger_collection = LoggerCollection([logger1, logger2])
-    with pytest.deprecated_call(match=logger_collection_dep):
+    with pytest.deprecated_call(match="`LoggerCollection` is deprecated in v1.6"):
         logger_collection_2 = LoggerCollection([logger2])
 
     trainer = Trainer()
@@ -68,7 +67,7 @@ def test_trainer_loggers_setters():
     assert trainer.loggers == [logger1]
 
     trainer.logger = logger_collection
-    with pytest.deprecated_call(match=logger_collection_dep):
+    with pytest.deprecated_call(match="`LoggerCollection` is deprecated in v1.6"):
         assert trainer.logger._logger_iterable == logger_collection._logger_iterable
     assert trainer.loggers == [logger1, logger2]
 
@@ -84,7 +83,7 @@ def test_trainer_loggers_setters():
     # Test setters for trainer.loggers
     trainer.loggers = [logger1, logger2]
     assert trainer.loggers == [logger1, logger2]
-    with pytest.deprecated_call(match=logger_collection_dep):
+    with pytest.deprecated_call(match="`LoggerCollection` is deprecated in v1.6"):
         assert trainer.logger._logger_iterable == logger_collection._logger_iterable
 
     trainer.loggers = [logger1]

From 26ddec96f01fd3cfa0e945a84238746037f12c2f Mon Sep 17 00:00:00 2001
From: Akash Kwatra <akashkw@gmail.com>
Date: Tue, 1 Mar 2022 12:12:18 -0800
Subject: [PATCH 06/10] update warning message

---
 pytorch_lightning/trainer/trainer.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pytorch_lightning/trainer/trainer.py b/pytorch_lightning/trainer/trainer.py
index ce9d3ae68bd84..fc26ce436c741 100644
--- a/pytorch_lightning/trainer/trainer.py
+++ b/pytorch_lightning/trainer/trainer.py
@@ -2600,7 +2600,7 @@ def logger(self) -> Optional[LightningLoggerBase]:
             return self.loggers[0]
         else:
             rank_zero_warn(
-                "Using `trainer.logger` when Trainer is configured to use multiple loggers."
+                "You are using `trainer.logger` when the Trainer is configured to use multiple loggers."
                 " This behavior will change in v1.8 such that `trainer.logger` will return the first"
                 " logger in `trainer.loggers`."
             )

From 80fad1797eec1aff95c2ae9811713fc1d3aa86df Mon Sep 17 00:00:00 2001
From: ananthsub <ananth.subramaniam@gmail.com>
Date: Tue, 1 Mar 2022 19:54:13 -0800
Subject: [PATCH 07/10] Update pytorch_lightning/trainer/trainer.py

---
 pytorch_lightning/trainer/trainer.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pytorch_lightning/trainer/trainer.py b/pytorch_lightning/trainer/trainer.py
index fc26ce436c741..46e9aeb368c90 100644
--- a/pytorch_lightning/trainer/trainer.py
+++ b/pytorch_lightning/trainer/trainer.py
@@ -2600,9 +2600,9 @@ def logger(self) -> Optional[LightningLoggerBase]:
             return self.loggers[0]
         else:
             rank_zero_warn(
-                "You are using `trainer.logger` when the Trainer is configured to use multiple loggers."
-                " This behavior will change in v1.8 such that `trainer.logger` will return the first"
-                " logger in `trainer.loggers`."
+                "Using trainer.logger when Trainer is configured to use multiple loggers."
+                " This behavior will change in v1.8 when LoggerCollection is removed, and"
+                " trainer.logger will return the first logger in trainer.loggers"
             )
             return LoggerCollection(self.loggers)
 

From 9a3c3f6d848b099ee4229c5c670419b88da0feb4 Mon Sep 17 00:00:00 2001
From: Akash Kwatra <akashkw@gmail.com>
Date: Wed, 2 Mar 2022 15:30:53 -0800
Subject: [PATCH 08/10] Update deprecation message

---
 pytorch_lightning/loggers/base.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/pytorch_lightning/loggers/base.py b/pytorch_lightning/loggers/base.py
index dae253e393433..dc50d48b23670 100644
--- a/pytorch_lightning/loggers/base.py
+++ b/pytorch_lightning/loggers/base.py
@@ -222,7 +222,8 @@ class LoggerCollection(LightningLoggerBase):
     """The :class:`LoggerCollection` class is used to iterate all logging actions over the given `logger_iterable`.
 
     .. deprecated:: v1.6
-        `LoggerCollection` is deprecated in v1.6 in favor of `trainer.loggers` and will be removed in v1.8.
+        `LoggerCollection` is deprecated in v1.6 and will be removed in v1.8.
+        Directly pass a list of loggers to the Trainer and access the list via the `trainer.loggers` attribute.
 
     Args:
         logger_iterable: An iterable collection of loggers
@@ -232,7 +233,8 @@ def __init__(self, logger_iterable: Iterable[LightningLoggerBase]):
         super().__init__()
         self._logger_iterable = logger_iterable
         rank_zero_deprecation(
-            "`LoggerCollection` is deprecated in v1.6 in favor of `trainer.loggers` and will be removed in v1.8."
+            "`LoggerCollection` is deprecated in v1.6 and will be removed in v1.8. Directly pass a list of loggers"
+            " to the Trainer and access the list via the `trainer.loggers` attribute."
         )
 
     def __getitem__(self, index: int) -> LightningLoggerBase:

From d7e1f2e8f6dfbacd6c3ade672117746782ae4b43 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Adrian=20W=C3=A4lchli?= <aedu.waelchli@gmail.com>
Date: Fri, 4 Mar 2022 22:02:52 +0100
Subject: [PATCH 09/10] suppress deprecation warning triggered internally

---
 pytorch_lightning/trainer/trainer.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/pytorch_lightning/trainer/trainer.py b/pytorch_lightning/trainer/trainer.py
index 4c01e58e9e3d5..881b62271ec73 100644
--- a/pytorch_lightning/trainer/trainer.py
+++ b/pytorch_lightning/trainer/trainer.py
@@ -2623,7 +2623,9 @@ def logger(self) -> Optional[LightningLoggerBase]:
                 " This behavior will change in v1.8 when LoggerCollection is removed, and"
                 " trainer.logger will return the first logger in trainer.loggers"
             )
-            return LoggerCollection(self.loggers)
+            with warnings.catch_warnings():
+                warnings.simplefilter("ignore")
+                return LoggerCollection(self.loggers)
 
     @logger.setter
     def logger(self, logger: Optional[LightningLoggerBase]) -> None:

From 13d74094f55c873d7fc36458797dc7abc9aabdf3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Adrian=20W=C3=A4lchli?= <aedu.waelchli@gmail.com>
Date: Fri, 4 Mar 2022 22:20:48 +0100
Subject: [PATCH 10/10] fix test for unwanted deprecation message

---
 tests/deprecated_api/test_remove_1-8.py  | 4 +---
 tests/trainer/properties/test_loggers.py | 6 ++----
 2 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/tests/deprecated_api/test_remove_1-8.py b/tests/deprecated_api/test_remove_1-8.py
index a9db8e51fbcdc..3c8923a96c3ad 100644
--- a/tests/deprecated_api/test_remove_1-8.py
+++ b/tests/deprecated_api/test_remove_1-8.py
@@ -673,9 +673,7 @@ def test_v1_8_0_logger_collection(tmpdir):
     trainer1.logger
     trainer1.loggers
     trainer2.loggers
-
-    with pytest.deprecated_call(match="`LoggerCollection` is deprecated in v1.6"):
-        trainer2.logger
+    trainer2.logger
 
     with pytest.deprecated_call(match="`LoggerCollection` is deprecated in v1.6"):
         LoggerCollection([logger1, logger2])
diff --git a/tests/trainer/properties/test_loggers.py b/tests/trainer/properties/test_loggers.py
index 3b3ffeea44310..b48f3f2768175 100644
--- a/tests/trainer/properties/test_loggers.py
+++ b/tests/trainer/properties/test_loggers.py
@@ -67,8 +67,7 @@ def test_trainer_loggers_setters():
     assert trainer.loggers == [logger1]
 
     trainer.logger = logger_collection
-    with pytest.deprecated_call(match="`LoggerCollection` is deprecated in v1.6"):
-        assert trainer.logger._logger_iterable == logger_collection._logger_iterable
+    assert trainer.logger._logger_iterable == logger_collection._logger_iterable
     assert trainer.loggers == [logger1, logger2]
 
     # LoggerCollection of size 1 should result in trainer.logger becoming the contained logger.
@@ -83,8 +82,7 @@ def test_trainer_loggers_setters():
     # Test setters for trainer.loggers
     trainer.loggers = [logger1, logger2]
     assert trainer.loggers == [logger1, logger2]
-    with pytest.deprecated_call(match="`LoggerCollection` is deprecated in v1.6"):
-        assert trainer.logger._logger_iterable == logger_collection._logger_iterable
+    assert trainer.logger._logger_iterable == logger_collection._logger_iterable
 
     trainer.loggers = [logger1]
     assert trainer.loggers == [logger1]