class TechStack:
    def __init__(self):
        self.programmingLanguages = ["Python", "JavaScript", "C", "C++"]
        self.webDevelopment = ["HTML", "CSS", "JS", "React"]
        self.appDevelopment = ["Dart" , "Swift" , "SwiftUI" ,"UIKit"]
        self.versionControl = ["Git"]
        self.cloudServices = ["AWS"]
        self.pythonLibraries = ["TensorFlow", "Keras", "NumPy", "Pandas", "Seaborn", "Matplotlib", "PyTorch", "Langchain"]
        self.databases = ["MySQL", "MongoDB","postgres","Firebase"]
        self.backendFrameworks = ["Django", "Flask","Express","Node"]

    def __str__(self):
        return "Tech stack initialized!"

techStack = TechStack()
print(techStack)