Maybe I'm missing something, but a lot of these answers seem overly complicated. You should be able to just set the columns within a single list:
Column to the front:
df = df[ ['Mid'] + [ col for col in df.columns if col != 'Mid' ] ]
Or if instead, you want to move it to the back:
df = df[ [ col for col in df.columns if col != 'Mid' ] + ['Mid'] ]
Or if you wanted to move more than one column:
cols_to_move = ['Mid', 'Zsore']
df = df[ cols_to_move + [ col for col in df.columns if col not in cols_to_move ] ]