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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def locate_arcgis():
  '''
  Find the path to the ArcGIS Desktop installation.

  Keys to check:

  HLKM/SOFTWARE/ESRI/ArcGIS 'RealVersion' - will give the version, then we can use
  that to go to
  HKLM/SOFTWARE/ESRI/DesktopXX.X 'InstallDir'. Where XX.X is the version

  We may need to check HKLM/SOFTWARE/Wow6432Node/ESRI instead
  '''
  try:
    key = _winreg.OpenKey(_winreg.HKEY_LOCAL_MACHINE,
                          'SOFTWARE\\Wow6432Node\\ESRI\\ArcGIS', 0)

    version = _winreg.QueryValueEx(key, "RealVersion")[0][:4]

    key_string = "SOFTWARE\\Wow6432Node\\ESRI\\Desktop{0}".format(version)
    desktop_key = _winreg.OpenKey(_winreg.HKEY_LOCAL_MACHINE,
                                  key_string, 0)

    install_dir = _winreg.QueryValueEx(desktop_key, "InstallDir")[0]
    return install_dir
  except WindowsError:
    raise ImportError("Could not locate the ArcGIS directory on this machine")