Element Tree: How to find all child elements with a specific value

Question

I have an XML file with following structure:

<?xml version="1.0"?>
<data>
<product>
    <Product_Code>code1</Product_Code>
    <Size>x</Size>
    <Quantity>1<Quantity>
</product>
<product>
    <Product_Code>code3</Product_Code>
    <Size>c</Size>
    <Quantity>5<Quantity>
</product>
<product>
    <Product_Code>code2</Product_Code>
    <Size>z</Size>
    <Quantity>2<Quantity>
</product>
<product>
    <Product_Code>code3</Product_Code>
    <Size>a</Size>
    <Quantity>1<Quantity>
</product>
<product>
    <Product_Code>code1</Product_Code>
    <Size>y</Size>
    <Quantirt>1<Quantity>
</product>
<product>
    <Product_Code>code3</Product_Code>
    <Size>b</Size>
    <Quantity>5<Quantity>
</product>
</data>

There are products in the XML. Each product has a code,size and quantoty. Code can be common.

I want to select all different size corresponding to each code and quantity corresponding to each size. i.e: {code1: {x:1, y:1}, code2: {z:2}, code3: {a:1,b:5,c:5}

EDIT: I want to do it on the go. E.g. If iterate through the child elements as:

tree = ET.parse(file)
root = tree.getroot()
for child in root:
    code = child.find('Product_Code')

If code = "code1", I'd like to find all other elements in the root withcode = "code1" and their corresponding size and quantity value.

I want to generate following XML:

<products>
    <product>
        <Product_Code>code1<Product_Code>
        <variants>
            <variant>
                <size>x</size>
                <quantity>1</quantity>
            </variant>
            <variant>
                <size>y</size>
                <quantity>1</quantity>
            </variant>
        </variants>
    </product>
    <product>
        <Product_Code>code2<Product_Code>
        <variants>
            <variant>
                <size>z</size>
                <quantity>2</quantity>
            </variant>
        </variants>
    </product>
    <product>
        <Product_Code>code3<Product_Code>
        <variants>
            <variant>
                <size>a</size>
                <quantity>1</quantity>
            </variant>
            <variant>
                <size>b</size>
                <quantity>5</quantity>
            </variant>
            <variant>
                <size>c</size>
                <quantity>5</quantity>
            </variant>
        </variants>
    </product>
</products>

Answer 1

First of all, your xml is not valid, see mismatched Quantiry and Quantity tags.

Anyway, here's how you can get, for example, all of the sizes per code:

from xml.etree import ElementTree as ET


data = """<?xml version="1.0"?>
<data>
<product>
    <Product_Code>code1</Product_Code>
    <Size>x</Size>
    <Quantity>1</Quantity>
</product>
<product>
    <Product_Code>code3</Product_Code>
    <Size>c</Size>
    <Quantity>5</Quantity>
</product>
<product>
    <Product_Code>code2</Product_Code>
    <Size>z</Size>
    <Quantity>2</Quantity>
</product>
<product>
    <Product_Code>code3</Product_Code>
    <Size>a</Size>
    <Quantity>1</Quantity>
</product>
<product>
    <Product_Code>code1</Product_Code>
    <Size>y</Size>
    <Quantity>1</Quantity>
</product>
<product>
    <Product_Code>code3</Product_Code>
    <Size>b</Size>
    <Quantity>5</Quantity>
</product>
</data>"""

tree = ET.fromstring(data)

codes = {}
for product in tree.findall('.//product'):
    code = product.find('Product_Code').text
    size = product.find('Size').text
    quantity = product.find('Quantity').text

    codes[code] = codes[code] if code in codes else {}
    codes[code][size] = quantity

print codes

prints:

{'code1': {'y': '1', 'x': '1'}, 'code2': {'z': '2'}, 'code3': {'a': '1', 'c': '5', 'b': '5'}}