How to unpivot a Pandas dataframe on two ID fields with multiple sets of columns

I have a pandas Dataframe that looks like this:

Now I want to unpivot it on pid and fid so that it would become this:

How do I do this?

You can use melt and then pivot_table:

id_cols = ["pid", "fid"]

df = df.melt(id_vars=id_cols, var_name="ReasonType", value_name="Value")
df[["reason", "type"]] = df["ReasonType"].str.extract(r"(\w+Reason)(Name|Value)")
df = (
    df.pivot_table(
        index=id_cols + ["reason"], columns="type", values="Value", aggfunc="first"
    )
    .reset_index()
    .drop(columns="reason")
)
df.columns.name = None

   pid fid Name Value
0    1   x    a     3
1    1   x    b   8.2
2    2   y    c     8
3    2   y    d   7.0