How can a pandas merge preserve order?

Question

I have two DataFrames in pandas, trying to merge them. But pandas keeps changing the order. I\'ve tried setting indexes, resetting them, no matter what I do, I can\'t get th

Answer 1

Use pd.merge_ordered(), documentation here.

For your example,

z = pd.merge_ordered(x, y, how='left', on='state')

EDIT: Just wanted to point out that default behavior for this function is an outer merge, different from the default behavior of the more common .merge()