ValueError: xpath does not return any nodes. pandas error in python-CodePudding

I am trying to create a dataframe by adding a condition to pick up only the uptill a certain attribute say "stack".

I have pandas 1.3.4 installed in my windows 10 and spyder IDE.

import pandas as pd

df_employee = pd.read_xml('employee.xml',xpath='employee_name')
df_cor = pd.read_xml('employee.xml',xpath='employee_name/email')
df_id = pd.read_xml('employee.xml',xpath='employee_name/email/id')
df_id2 = pd.read_xml('employee.xml',xpath='//id')
df_address = pd.read_xml('employee.xml',xpath='employee_name/email/id/address')
df_address2 = pd.read_xml('employee.xml',xpath='//address')
df_street = pd.read_xml('employee.xml',xpath='employee_name/email/id/address/street')
df_street2 = pd.read_xml('employee.xml',xpath='//street')
df_state = pd.read_xml('employee.xml',xpath='employee_name/email/id/address/street/state')
df_cell_cap = pd.read_xml('employee.xml',xpath='employee_name/email/id[@name="stack"]//address')
df_street_stack = pd.read_xml('employee.xml',xpath='employee_name/email/id[@name="stack"]//street')

The code works fine uptill this stage but when it hits the below line it throws error.

df_cell_cap = pd.read_xml('employee.xml',xpath='employee_name/email/id[@name="stack"]//address')

I have tried the below ways but the error is still there.

df_address_stack = pd.read_xml('employee.xml',xpath='employee_name/email/id[contains(@name,"stack")]//address')
df_address_stack = pd.read_xml('employee.xml',xpath='employee_name/email/id/*[name() = 'stack']/address'

Error:

ValueError: xpath does not return any nodes. Be sure row level nodes are in xpath. If document uses namespaces denoted with xmlns, be sure to define namespaces and use them in xpath.

Is there anything that i am missing ? Below is my sample xml:

<?xml version="1.0" encoding="UTF-8"?>
<employee_name name="ndlkjfidm" date="dfhkryi">
    <email name="nnn" P="ffgnp" V="0.825" T="125c">
        <id name="stack">
            <address name="adas_jk3" type="entry">
                <street name="VSS" voltage="0.000000" vector="!ENXB" active_input="NA" active_ouput="ENX">
                    <temp name="ADS_DEFAULT_temp_LOW">
                        <raw nod="VBP" alt="7.05537e-15" jus="74.4619" />
                        <raw nod="VDDC" alt="4.63027e-10" jus="115.178" />
                    </temp>
                </street>
                <street name="VSS" voltage="0.000000" vector="ENXB" active_input="NA" active_ouput="ENX">
                    <temp name="ADS_DEFAULT_temp_HIGH">
                        <raw nod="VBP" alt="7.05537e-15" jus="74.4644" />
                        <raw nod="VDDC" alt="1.52578e-14" jus="311.073" />
                    </temp>
                </street>
            </address>
        </id>
    </email>
</employee_name>

CodePudding user response：

Your sample XML :

<employee_name name="ndlkjfidm" date="dfhkryi">
    <email name="nnn" P="ffgnp" V="0.825" T="125c">
        <id name="stack">
            <address name="adas_jk3" type="entry">
                <street name="VSS" voltage="0.000000" vector="!ENXB" active_input="NA" active_ouput="ENX">
                    <temp name="ADS_DEFAULT_temp_LOW">
                        <raw nod="VBP" alt="7.05537e-15" jus="74.4619" />
                        <raw nod="VDDC" alt="4.63027e-10" jus="115.178" />
                    </temp>
                </street>
                <street name="VSS" voltage="0.000000" vector="ENXB" active_input="NA" active_ouput="ENX">
                    <temp name="ADS_DEFAULT_temp_HIGH">
                        <raw nod="VBP" alt="7.05537e-15" jus="74.4644" />
                        <raw nod="VDDC" alt="1.52578e-14" jus="311.073" />
                    </temp>
                </street>
            </address>
        </id>
    </email>
</employee_name>

If you go through the documentation for pandas.read_xml, you will find that xpath needs to be specified with a // prefix. You may or may not specify . period before slashes.

So your code should work fine with the following change

df_employee = pd.read_xml(filename,xpath='//employee_name')

        name     date  email
0  ndlkjfidm  dfhkryi    NaN

df_cor = pd.read_xml(filename,xpath='//employee_name/email')

  name      P      V     T  id
0  nnn  ffgnp  0.825  125c NaN

df_id = pd.read_xml(filename,xpath='//employee_name/email/id')

    name  address
0  stack      NaN

df_address_stack = pd.read_xml(filename,xpath='//employee_name/email/id[contains(@name,"stack")]//address')

   name   type  street
0  adas_jk3  entry     NaN

which gives us the expected output

CodePudding user response：

Use:

df_id = pd.read_xml('employee.xml',xpath="//employee_name/email/id[contains(@name, 'stack')]")

Output:

    name    address
0   stack   NaN