# append row to dataframe without index
a_row = pd.Series([1, 2])
df = pd.DataFrame([[3, 4], [5, 6]])
row_df = pd.DataFrame([a_row])
df = pd.concat([row_df, df], ignore_index=True)
print(df)
# OUTPUT
# 0 1
# 0 1 2
# 1 3 4
# 2 5 6
# append row to dataframe with index
a_row = pd.Series([1, 2])
df = pd.DataFrame([[3, 4], [5, 6]], index = ["row1", "row2"])
row_df = pd.DataFrame([a_row], index = ["row3"])
df = pd.concat([row_df, df])
print(df)
# OUTPUT
# 0 1
# row3 1 2
# row1 3 4
# row2 5 6