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YAML: The Norway Problem

January 11, 2022April 8, 2023 2 Comments on YAML: The Norway Problem

[yaml-e1641935644383-560x194]

Earlier this week, Haroen Viaene posted this tweet about YAML:

    worst part of yaml: https://yaml.org/type/bool.html

    -- Haroen Viaene (@haroenv) January 10, 2022

The linked-to page contains the documentation on what defines a
boolean in YAML, and details that it can be parsed using this regex:

y|Y|yes|Yes|YES|n|N|no|No|NO
|true|True|TRUE|false|False|FALSE
|on|On|ON|off|Off|OFF

~

The reason to why this is problematic in some cases, is "The Norway
Problem" YAML has: when you abbreviate Norway to its ISO 3166-1
ALPHA-2 form NO, YAML will return false when parsing it:

countries:
- GB
- IE
- FR
- DE
- NO

>>> from pyyaml import load
>>> load(the_configuration)
{'countries': ['GB', 'IE', 'FR', 'DE', False]}

 The solution is to either escape these values in double quotes, or
to use a library -- such as StrictYAML for Python -- that won't convert
NO to False.

~

Other problematic values in YAML are version numbers that end in .0
and a lastname such as Null. By default these get converted to
numbers or NULL respectively.

The Norway Problem -
StrictYAML -

Posted byBramus!January 11, 2022April 8, 2023Posted inElsewhereTags: 
link, yaml

Published by Bramus!

Bramus is a frontend web developer from Belgium, working as a Chrome
Developer Relations Engineer at Google. From the moment he discovered
view-source at the age of 14 (way back in 1997), he fell in love with
the web and has been tinkering with it ever since (more ...) View more
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Join the Conversation

 1. [3c98114]
 2. [c47bf5e]

2 Comments

 1. [3c98114]Steve says:
    March 25, 2023 at 10:08 am

    ISO 3116 is about magnesium and magnesium alloys; I think you
    mean ISO 3166.

    Reply
     1. [c47bf5e]Bramus! says:
        April 8, 2023 at 11:12 am

        Hahaha, great catch! 

        Reply

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