ensure_elementtree_imported

xlsx.py

ET = None
ET_has_iterparse = False

def ensure_elementtree_imported(verbosity, logfile):
    global ET, ET_has_iterparse
    if ET is not None:
        return
    if "IronPython" in sys.version:
        import xml.etree.ElementTree as ET
        #### 2.7.2.1: fails later with 
        #### NotImplementedError: iterparse is not supported on IronPython. (CP #31923)
    else:
        try: import xml.etree.cElementTree as ET
        except ImportError:
            try: import cElementTree as ET
            except ImportError:
                try: import lxml.etree as ET
                except ImportError:
                    try: import xml.etree.ElementTree as ET
                    except ImportError:
                        try: import elementtree.ElementTree as ET
                        except ImportError:
                            raise Exception("Failed to import an ElementTree implementation")
    if hasattr(ET, 'iterparse'):
        _dummy_stream = BYTES_IO(b'')
        try:
            ET.iterparse(_dummy_stream)
            ET_has_iterparse = True
        except NotImplementedError:
            pass
    if verbosity:
        etree_version = repr([
            (item, getattr(ET, item))
            for item in ET.__dict__.keys()
            if item.lower().replace('_', '') == 'version'
            ])
        print(ET.__file__, ET.__name__, etree_version, ET_has_iterparse, file=logfile)