The Power of XML: Simplifying Data Exchange and Storage
Learning the basics of XML and how to deal with it in Python
XML stands for Extensible Markup Language and is used today as a text-based data format for the exchange of structured data. It was originally developed to replace HTML because it had reached its limits in terms of data technology.
How are XML files structured?
The so-called markup languages, such as HTML or XML, use markup to structure textual information. In HTML there is a fixed set of markers, which are defined in angle brackets (<>). These include, for example, headings (
,
,
, …) or paragraphs (
), which are used to build up the structure of a website:
<!DOCTYPE html>
<html>
<head>
<title>Title Text</title>
</head> <body>
<h1>Main Header</h1>
<p>The first paragraph</p>
</body> </html>For example, this is the structure of a very simple website. The markups define the structure of the page, which currently consists only of a heading and a short paragraph.
XML uses the same structure with the difference that the amount of markups is not limited and their namings are freely selectable. This makes it relatively easy to emulate many types of data structures.
The only rules given by Extensible Markup Language are that markups must always start with an opening tag
To display nested information, several new tags can also be defined within an open tag. Here is an example:
Additional functionality is the so-called parameters. These can be defined for each markup and must always contain a name and a value. The value must be defined in quotes, even if it is a number.
In our example, the introduction of parameters is useful when we want to describe multiple cars in a collection:
Advantages and Disadvantages of the Extensible Markup Language
The following advantages are offered by the use of Extensible Markup Language files:
- Wide distribution and thus high compatibility with already existing applications
- High security of the files
- Easy recovery of information due to the readability of the text files
- Easy interpretation by man and machine
- Simple structure and layout, so that it can be quickly understood by many users
- Extensibility in the form of “dialects”
The only real drawback to this long list of positives comes from the textual format that the Extensible Markup Language uses. Textual information can only be stored with comparatively more memory and can therefore lead to lower performance in processing. Binary file formats, such as BSON, require significantly less storage space for the same information but are not human-readable because the information is stored in zeros and ones.
Which Applications use the Extensible Markup Language?
Due to the text-based storage of the Extensible Markup Language, the format is relatively easy to read and understand. This is why it is used for a wide variety of applications. One of the most common use cases is data exchange, i.e. importing and exporting data in applications. This is what makes it so valuable for Data Scientists. Also, it is very easy to import into Python and handle it like a Python Dictionary.
In addition, there are few general uses of the Extensible Markup Language, as most use cases have created a variation of XML that is specific to their application. For example, there is the Mathematical Markup Language (MathML), which is a dialect of XML and is used to correctly represent mathematical equations and terms.
How to edit XML Files in Python?
There are several ways and modules to open XML files in Python. We will try to use a string consisting of our previous example. We can either try to preserve the original structure:
On the other hand, we can also try to convert the structure of the Extensible Markup Language into a Python dictionary. This is much easier for many developers who work a lot with Python:
What does the future of XML look like?
The Extensible Markup Language has been around since the late 1990s and has played an important role in data exchange and interoperability on the Internet. Although its dominance has been challenged somewhat in recent years, it still has a number of advantages that make it a valuable tool for representing and exchanging data. The following are some possible futures for XML:
- Continued use in legacy systems: Many large enterprises have invested heavily in XML-based technologies and infrastructures and will likely continue to rely on XML in the coming years. As a result, XML is likely to remain an important technology for representing and exchanging data in a number of areas, including healthcare, finance, and government.
- Competition from JSON: JSON (JavaScript Object Notation) is a lightweight data exchange format that has gained popularity in recent years, especially for Web-based applications. JSON has some advantages over XML, including simpler syntax and better support for hierarchical data structures. However, XML still has some advantages over JSON, such as more robust support for namespaces and a wider range of tools and technologies for working with data.
- Integration with other technologies: XML is often used in conjunction with other technologies, such as XSLT (Extensible Stylesheet Language Transformations) for transforming data, XPath for navigating documents, and XQuery for querying data. With the advent of new technologies such as the semantic web and linked data, XML may find new uses and use cases.
- Evolution of XML standards: it is a mature technology, but one that is constantly evolving. The World Wide Web Consortium (W3C) is responsible for maintaining and developing the XML standard, and new versions of the standard are released regularly. As the needs of the Web and the broader technological ecosystem evolve, the XML standard is likely to evolve as well.
Although XML must compete with newer technologies, it continues to play an important role in the representation and exchange of data, particularly in areas where interoperability and data standardization are critical. As technology continues to evolve, it will be interesting to see how XML continues to adapt and evolve to meet the needs of the Web and the broader technology ecosystem.
This is what you should take with you
- XML stands for Extensible Markup Language and is used today as a text-based data format for the exchange of structured data.
- Due to the text-based storage of the Extensible Markup Language, the format is relatively easy to read and understand.
- Among other things, the format has the advantage of being adaptable to different use cases through dialects.
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