old_contents: import os, sys; sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))
  
  import fnmatch
  
  import numpy as np
  import pytest
  
  import lasio
  
  test_dir = os.path.dirname(__file__)
  
  egfn = lambda fn: os.path.join(os.path.dirname(__file__), "examples", fn)
  stegfn = lambda vers, fn: os.path.join(
      os.path.dirname(__file__), "examples", vers, fn)
  
  def test_delete_curve():
      l = lasio.read(egfn("sample.las"))
      shape = l.data.shape[1]
      curve = l.curves.keys()[1]
      l.delete_curve(curve)
      assert curve not in l.curves.keys()
      assert len(l.curves.keys()) == (shape - 1)
      assert l.curves.keys() == ['DEPT', 'RHOB', 'NPHI', 'SFLU', 'SFLA','ILM', 'ILD']
  
  def test_delete_section_item_by_index():
      las = lasio.read(egfn('sample.las'))
      del las.params[1]
      assert las.params.keys() == ['BHT', 'FD', 'MATR', 'MDEN', 'RMF', 'DFD']
  
  def test_delete_section_item_by_mnemonic():
      las = lasio.read(egfn('sample.las'))
      del las.params['MDEN']
      assert las.params.keys() == ['BHT', 'BS', 'FD', 'MATR', 'RMF', 'DFD']
new_contents: import os, sys; sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))
  
  import fnmatch
  
  import numpy as np
  import pytest
  
  import lasio
  
  test_dir = os.path.dirname(__file__)
  
  egfn = lambda fn: os.path.join(os.path.dirname(__file__), "examples", fn)
  stegfn = lambda vers, fn: os.path.join(
      os.path.dirname(__file__), "examples", vers, fn)
  
  def test_delete_curve():
      las = lasio.read(egfn("sample.las"))
      del las.curves['DT']
      assert las.curves.keys() == ['DEPT', 'RHOB', 'NPHI', 'SFLU', 'SFLA','ILM', 'ILD']
  
  def test_delete_section_item_by_index():
      las = lasio.read(egfn('sample.las'))
      del las.params[1]
      assert las.params.keys() == ['BHT', 'FD', 'MATR', 'MDEN', 'RMF', 'DFD']
  
  def test_delete_section_item_by_mnemonic():
      las = lasio.read(egfn('sample.las'))
      del las.params['MDEN']
      assert las.params.keys() == ['BHT', 'BS', 'FD', 'MATR', 'RMF', 'DFD']
subject: add final test for #155 (del las.curves[mnemonic])