Use .comet.config file for CometLogger (#1913)

* Use .comet.config file or env var for API key.

* Make CometLogger API key changes backwards compatible.

* Fix line too long.

* Add documentation about loading from ~/.comet_config.

* Update required comet_ml version.

* Comet logger: allow offline experiments with config file.

This adds a new argument to the logger to control the online / offline mode explicitly so that if you give an API key and a save_dir (e.g. to control where checkpoints go while having ~/.comet.config) you can specify which mode you want.

* Make CometLogger API key changes backwards compatible.

* Comet logger: change online argument to be offline.

For consistency with other loggers.

* chlog

Co-authored-by: Jirka Borovec <jirka@pytorchlightning.ai>

CHANGELOG.md

@@ -41,12 +41,14 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 
 - Truncated long version numbers in progress bar ([#2594](https://github.com/PyTorchLightning/pytorch-lightning/pull/2594))
 
-- Enable val/test loop disabling ([#2692](https://github.com/PyTorchLightning/pytorch-lightning/pull/2692))
+- Enabling val/test loop disabling ([#2692](https://github.com/PyTorchLightning/pytorch-lightning/pull/2692))
 
-- Refactor into `accelerator` module:
+- Refactored into `accelerator` module:
     * GPU training ([#2704](https://github.com/PyTorchLightning/pytorch-lightning/pull/2704))
     * TPU training ([#2708](https://github.com/PyTorchLightning/pytorch-lightning/pull/2708))
 
+- Using .comet.config file for CometLogger ([#1913](https://github.com/PyTorchLightning/pytorch-lightning/pull/1913))
+
 ### Deprecated
 
 - Deprecated Trainer attribute `ckpt_path`, which will now be set by `weights_save_path` ([#2681](https://github.com/PyTorchLightning/pytorch-lightning/pull/2681))

environment.yml

@@ -44,7 +44,7 @@ dependencies:
     - pip:
         - test-tube>=0.7.5
         - mlflow>=1.0.0
-        - comet_ml>=1.0.56
+        - comet_ml>=3.1.12
         - wandb>=0.8.21
         - neptune-client>=0.4.109
         - horovod>=0.19.1

pytorch_lightning/loggers/comet.py

@@ -16,8 +16,7 @@ try:
     except ImportError:  # pragma: no-cover
         # For more information, see: https://www.comet.ml/docs/python-sdk/releases/#release-300
         from comet_ml.papi import API  # pragma: no-cover
-
-    _COMET_AVAILABLE = True
+    from comet_ml.config import get_config, get_api_key
 except ImportError:  # pragma: no-cover
     CometExperiment = None
     CometExistingExperiment = None
@@ -25,6 +24,8 @@ except ImportError:  # pragma: no-cover
     CometBaseExperiment = None
     API = None
     _COMET_AVAILABLE = False
+else:
+    _COMET_AVAILABLE = True
 
 
 import torch
@@ -78,8 +79,11 @@ class CometLogger(LightningLoggerBase):
         >>> trainer = Trainer(logger=comet_logger)
 
     Args:
-        api_key: Required in online mode. API key, found on Comet.ml
-        save_dir: Required in offline mode. The path for the directory to save local comet logs
+        api_key: Required in online mode. API key, found on Comet.ml. If not given, this
+            will be loaded from the environment variable COMET_API_KEY or ~/.comet.config
+            if either exists.
+        save_dir: Required in offline mode. The path for the directory to save local
+            comet logs. If given, this also sets the directory for saving checkpoints.
         workspace: Optional. Name of workspace for this user
         project_name: Optional. Send your experiment to a specific project.
             Otherwise will be sent to Uncategorized Experiments.
@@ -88,6 +92,10 @@ class CometLogger(LightningLoggerBase):
             This is used to determine version number
         experiment_name: Optional. String representing the name for this particular experiment on Comet.ml.
         experiment_key: Optional. If set, restores from existing experiment.
+        offline: If api_key and save_dir are both given, this determines whether
+            the experiment will be in online or offline mode. This is useful if you use
+            save_dir to control the checkpoints directory and have a ~/.comet.config
+            file but still want to run offline experiments.
     """
 
     def __init__(self,
@@ -98,6 +106,7 @@ class CometLogger(LightningLoggerBase):
                  rest_api_key: Optional[str] = None,
                  experiment_name: Optional[str] = None,
                  experiment_key: Optional[str] = None,
+                 offline: bool = False,
                  **kwargs):
 
         if not _COMET_AVAILABLE:
@@ -105,10 +114,15 @@ class CometLogger(LightningLoggerBase):
                               ' install it with `pip install comet-ml`.')
         super().__init__()
         self._experiment = None
-        self._save_dir = save_dir
 
         # Determine online or offline mode based on which arguments were passed to CometLogger
-        if api_key is not None:
+        api_key = api_key or get_api_key(None, get_config())
+
+        if api_key is not None and save_dir is not None:
+            self.mode = "offline" if offline else "online"
+            self.api_key = api_key
+            self._save_dir = save_dir
+        elif api_key is not None:
             self.mode = "online"
             self.api_key = api_key
         elif save_dir is not None:
@@ -116,7 +130,9 @@ class CometLogger(LightningLoggerBase):
             self._save_dir = save_dir
         else:
             # If neither api_key nor save_dir are passed as arguments, raise an exception
-            raise MisconfigurationException("CometLogger requires either api_key or save_dir during initialization.")
+            raise MisconfigurationException(
+                "CometLogger requires either api_key or save_dir during initialization."
+            )
 
         log.info(f"CometLogger will be initialized in {self.mode} mode")
 

requirements/extra.txt

@@ -1,7 +1,7 @@
 # extended list of package dependencies to reach full functionality
 
 neptune-client>=0.4.109
-comet-ml>=1.0.56
+comet-ml>=3.1.12
 mlflow>=1.0.0
 test_tube>=0.7.5
 wandb>=0.8.21