Pandas read_xml(): Import XML Data into a DataFrame
The `read_xml()` function in Pandas allows you to efficiently read data from XML files into a DataFrame. It supports parsing both simple and complex XML structures with options like XPath, attributes, and hierarchical data management.
⇓Download sample XML file: student.xml
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Basic Example
import pandas as pd
df = pd.read_xml('E:\\testing\\data\\student.xml', parser='etree')
print(df.head())
If the XML nodes contain attributes or specific data fields, you can extract them using lxml and convert the data into a Pandas DataFrame.
from lxml import etree
import pandas as pd
# Parse the XML filetree = etree.parse('student.xml')
# Extract data from <Row> elementsstudents = []
forrowintree.xpath('.//Row'): # Select all <Row> nodesstudents.append({
'id': row.findtext('id'), # Extract the text of <id>'class': row.findtext('class') # Extract the text of <class>
})
# Convert the extracted data to a DataFramedf = pd.DataFrame(students)
print(df)
### Output:
idclass01Four12Three23Three34Four45Four
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Using attrs_only to Extract Only Attributes
The attrs_only parameter in read_xml() extracts only the attributes of XML elements, ignoring their text content. This is especially useful when XML nodes contain both attributes and text. Here's an example:
import pandas as pd# Example XML with attributes and text content
xml_data = '''
<Students>
<Student id="1" name="John Deo" class="Four">Passed</Student>
<Student id="2" name="Max Ruin" class="Three">Failed</Student>
<Student id="3" name="Arnold" class="Three">Passed</Student>
</Students>
'''
# Reading XML with attrs_only=True
df_attrs_only = pd.read_xml(xml_data, parser='etree', attrs_only=True)
print("With attrs_only=True:")
print(df_attrs_only)
# Reading XML without attrs_only (default behavior)
df_default = pd.read_xml(xml_data, parser='etree')
print("\nWithout attrs_only (default):")
print(df_default)
### Output:
With attrs_only=True:
id name class
0 1 John Deo Four
1 2 Max Ruin Three
2 3 Arnold Three
Without attrs_only (default behavior):
id name class Student
0 1 John Deo Four Passed
1 2 Max Ruin Three Failed
2 3 Arnold Three Passed
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Explanation:
XML Structure: Each <Student> element contains attributes (id, name, class) and text content (Passed or Failed).
With attrs_only=True:
Only the attributes (id, name, class) are included in the DataFrame.
The text content (Passed or Failed) is ignored.
Without attrs_only:
Both the attributes and the text content are included.
The text content is added to a new column named after the XML element (Student).
Use Case: Use attrs_only=True when the text content of XML nodes is not relevant, and only the attributes are needed.
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Using namespaces to Handle Namespaced XML
The namespaces parameter in read_xml() allows you to parse XML files that use namespaces. Here's an example:
import pandas as pd# Example XML with namespaces
xml_data = '''
<ns:Students xmlns:ns="http://example.com/ns">
<ns:Student id="1" name="John Deo" class="Four">Passed</ns:Student>
<ns:Student id="2" name="Max Ruin" class="Three">Failed</ns:Student>
<ns:Student id="3" name="Arnold" class="Three">Passed</ns:Student>
</ns:Students>
'''
# Define the namespace
namespaces = {"ns": "http://example.com/ns"}
# Reading XML with the namespace
df = pd.read_xml(xml_data, xpath=".//ns:Student", namespaces=namespaces)
print(df)
### Output:
id name class Student
0 1 John Deo Four Passed
1 2 Max Ruin Three Failed
2 3 Arnold Three Passed
Explanation:
XML with Namespace:
The XML uses the namespace prefix ns with the URI http://example.com/ns.
Elements like <ns:Student> and <ns:Students> are namespaced.
Defining the Namespace:
The namespaces parameter is a dictionary where keys are prefixes (e.g., ns) and values are their respective URIs (e.g., http://example.com/ns).
Using XPath with Namespace:
Use the xpath parameter with the namespace prefix (e.g., .//ns:Student) to target specific elements.
Output:
The resulting DataFrame includes attributes (id, name, class) and text content (Passed or Failed).
Handling Nested XML
When the XML contains nested tags, such as scores grouped within a `` tag, `read_xml()` can parse these nested elements:
import pandas as pd
df = pd.read_xml('nested_student.xml')
print(df)
### Output:
id name marks.score1 marks.score2
0 1 John Deo 75.0 NaN
1 2 Max Ruin 85.0 80.0
2 3 Arnold 55.0 90.0
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Questions
What is the purpose of the read_xml() function in Pandas?
How can you use XPath to extract specific nodes from an XML file?
What are some common attributes of the read_xml() function?
Provide an example of reading XML data with specific attributes.
What is the purpose of the attrs_only attribute in read_xml()?
In which scenarios would you use attrs_only=True?
Provide an example where XML nodes contain both attributes and text. What changes in the DataFrame when attrs_only is used?
How does the attrs_only attribute help in simplifying XML data extraction?
What is the purpose of the namespaces parameter in read_xml()?
Provide an example of reading XML with namespaces using read_xml().
How does the xpath parameter work in conjunction with namespaces?
Why is defining namespaces important when working with namespaced XML?