Task Memo: Write a program using Python to format an XML string

Function:

1. Remove the extra spaces in the XML, line breaks, and make the XML string a line.

2. Add indents to the XML and use print to correctly print the string after the indentation is added.

Ideas:

Use regular expressions to determine the type of string in the XML:

1. File header

2. Determine the type of element: a label with attributes, a label with no attributes, a label that ends in a label, a label that contains only text, and a label that does not contain text.

3. Add a space after the line break according to the level of the label

' \ n '+i*     '

Task Memo: Write a program using Python to format an XML string