docstr: Plot a metric for this list of checkpoints. If no metric is specified,
  defaults to the shared primary metric.
docstr_tok: ["Plot","a","metric","for","this","list","of","checkpoints",".","If","no","metric","is","specified",",","defaults","to","the","shared","primary","metric","."]
code: def plot(
      self, metric: Optional[str] = None, logy=False, plot_only=False
  ):
      """
      Plot a metric for this list of checkpoints. If no metric is specified,
      defaults to the shared primary metric.
      """
      import matplotlib.pyplot as plt  # type: ignore
  
      if metric is None:
          metric = self.primary_metric()
  
      data = []
      for chk in self:
          if chk.metrics and metric in chk.metrics:
              data.append(chk.metrics[metric])
          else:
              data.append(None)
  
      every_checkpoint_has_step = True
      steps = []
      for chk in self:
          if chk.step is None:
              every_checkpoint_has_step = False
              break
          steps.append(chk.step)
      if not every_checkpoint_has_step:
          steps = list(range(len(data)))
  
      label = None
      if len(self) > 0:
          label = self[0]._experiment.short_id()
      plt.plot(steps, data, label=label)
  
      if not plot_only:
          plt.xlabel("step")
          plt.ylabel(metric)
          plt.legend(bbox_to_anchor=(1, 1))
  
          if logy:
              plt.yscale("log")
  
imports: import datetime
  import os
  import io
  import tempfile
  import json
  import sys
  import html
  from typing import Optional, Dict, Any, List, BinaryIO, TYPE_CHECKING, MutableSequence
  from .None import console
  from .json import CustomJSONEncoder
  from .metadata import rfc3339_datetime, parse_rfc3339
  from .validate import check_path
label_desc: Use image node_id 2 for calling the CheckpointList obj's underlying member method code with example usage: obj.plot(metric, logy, plot_only) without return types