code: def left_no_dup():
      return DataFrame(
          {
              "a": ["a", "b", "c", "d"],
              "b": ["cat", "dog", "weasel", "horse"],
          },
          index=range(4),
      )
  
imports: from datetime import datetime
  import numpy
  import pytest
  from pandas.errors import MergeError
  import pandas
  from pandas import DataFrame, Index, MultiIndex, date_range, period_range
  import pandas._testing
  from pandas.core.reshape.concat import concat
label_desc: Use image node_id 1 for calling a global function with example usage: left_no_dup() and returns: DataFrame