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pythonxml-parsinglxmlfindallmultiple-conditions

invalid predicate by searching with multiple variable condition lxml python


With lxml I try to parse a certain street in a certain stage from an XML file:

part of the XML file:

<jndi_values environment="Ontwikkel" street="str1">
  <jndi_value key="ecm-eds-configVersie48str1a" value="eds/config/valstr1a">ONT_Value_3str1a</jndi_value>
  <jndi_value key="str1a" value="eds/config/valstr1">ONT_Value_WWW4a</jndi_value>
</jndi_values>
<jndi_values environment="Ontwikkel" street="str2">
  <jndi_value key="ecm-eds-configVersie48str2a" value="eds/config/str2a">ONT_Value_str2a</jndi_value>
  <jndi_value key="4WWW8str2a" value="eds/config/cW8str2">ONT_Value_4str2a</jndi_value>
</jndi_values>

And I want to find for example environment="Ontwikkel" and street="str2", only those values.

I tried:

only_jndi_values = package_config.findall("jndi_values[@environment='" + current_environment + "' and street='" + current_street + "']/jndi_value")

and

only_jndi_values = package_config.findall("jndi_values[@environment='" + current_environment + "' and @street='" + current_street + "']/jndi_value")

but it throws this invalid predicate error:

File "src/lxml/etree.pyx", line 1553, in lxml.etree._Element.findall
File "src/lxml/_elementpath.py", line 322, in lxml._elementpath.findall
File "src/lxml/_elementpath.py", line 300, in lxml._elementpath.iterfind
File "src/lxml/_elementpath.py", line 283, in lxml._elementpath._build_path_iterator
File "src/lxml/_elementpath.py", line 229, in lxml._elementpath.prepare_predicate
SyntaxError: invalid predicate

How can I evaluate values of 2 attributes with lxml findall()?


Solution

  • .//jndi_values[@environment="Ontwikkel"][@street="str2"]

    
    from lxml import etree
    
    data = '''\
    <foo>
    <bar>
    <jndi_values environment="Ontwikkel" street="str1">
      <jndi_value key="ecm-eds-configVersie48str1a" value="eds/config/valstr1a">ONT_Value_3str1a</jndi_value>
      <jndi_value key="str1a" value="eds/config/valstr1">ONT_Value_WWW4a</jndi_value>
    </jndi_values>
    <jndi_values environment="Ontwikkel" street="str2">
      <jndi_value key="ecm-eds-configVersie48str2a" value="eds/config/str2a">ONT_Value_str2a</jndi_value>
      <jndi_value key="4WWW8str2a" value="eds/config/cW8str2">ONT_Value_4str2a</jndi_value>
    </jndi_values>
    </bar>
    </foo>
    '''
    
    environment = "Ontwikkel"
    street = "str2"
    
    tree = etree.fromstring(data)
    xpath = f'.//jndi_values[@environment="{environment}"][@street="{street}"]'
    
    print(xpath)
    
    for e in tree.findall(xpath):
        for s in e.itertext():
            print(repr(s))