The spelling of the word "Pyopen" can be explained using IPA phonetic transcription, which represents the sounds of language. In IPA, "Py" is pronounced as /paɪ/, which represents the diphthong "ai" as in "pie". "O" is pronounced as /oʊ/, which represents the diphthong "ow" as in "low". And "pen" is pronounced as /pɛn/, which represents the short "e" sound as in "pet" and the nasal "n" sound. Altogether, "Pyopen" is pronounced as /paɪ.oʊ.pɛn/.