I have bumped on unclear dict sorting behavior in Python. Assuming that I have following dict:

m_dict = {"a":4, "b":3, "c":2, "d":1}

And I’d like to sort it by the value:

a = sorted(m_dict.items(), key=lambda x: x[1], reverse=True)
b = sorted(m_dict.items(), key=lambda x: x[1], reverse=False)

That works as expected. However, when I convert it back to the dictionary:

a1 = dict(sorted(m_dict.items(), key=lambda x: x[1], reverse=True))
b1 = dict(sorted(m_dict.items(), key=lambda x: x[1], reverse=False))

both dictionaries have the same content, which is not what I expect, as I expect them have the same order as in a and b.
Any ideas what is the root cause?

I have actually looked at How do I sort a dictionary by value? and this question stems from that post