class_docstr: Note: the Gantt charts listed here are inspired by
  Dustin Arendt and Svitlana Volkova. ESTEEM: A Novel Framework for Qualitatively Evaluating and
  Visualizing Spatiotemporal Embeddings in Social Media. ACL System Demonstrations. 2017.
  http://www.aclweb.org/anthology/P/P17/P17-4005.pdf
  
  In order to use the make chart function, Altair must be installed.
class_docstr_tok: ["Note",":","the","Gantt","charts","listed","here","are","inspired","by","Dustin","Arendt","and","Svitlana","Volkova",".","ESTEEM",":","A","Novel","Framework","for","Qualitatively","Evaluating","and","Visualizing","Spatiotemporal","Embeddings","in","Social","Media",".","ACL","System","Demonstrations",".","2017.","http",":","\/\/www.aclweb.org\/anthology\/P\/P17\/P17-4005.pdf","In","order","to","use","the","make","chart","function",",","Altair","must","be","installed","."]
code: def _find_sequences(self, time_steps):
      min_timestep = None
      last_timestep = None
      sequences = []
      cur_sequence = []
      for cur_timestep in sorted(time_steps):
          if min_timestep is None:
              cur_sequence = [cur_timestep]
              min_timestep = cur_timestep
          elif not self.is_gap_between_sequences_func(
              last_timestep, cur_timestep
          ):
              cur_sequence.append(cur_timestep)
              min_timestep = cur_timestep
          else:
              sequences.append([cur_sequence[0], cur_sequence[-1]])
              cur_sequence = [cur_timestep]
          last_timestep = cur_timestep
      if len(cur_sequence) != []:
          sequences.append([cur_sequence[0], cur_sequence[-1]])
      return sequences
  
file_path: scattertext/scattertext/diachronic/GanttChart.py
imports: import numpy
  import pandas
  from scattertext.termranking import AbsoluteFrequencyRanker
  from scattertext.termscoring.RankDifference import RankDifference
label_desc: Use image node_id 7 for calling the GanttChart obj's underlying member method code with example usage: obj._find_sequences(time_steps) and returns: sequences