Append to dataframe with for loop

[nocoffeenoworkee]

I'm trying to loop through a list(y) and output by appending a row for each item to a dataframe.

y=[datetime.datetime(2017, 3, 29), datetime.datetime(2017, 3, 30), datetime.datetime(2017, 3, 31)]

Desired Output:

Output:
Index                 Mean             Last
2017-03-29        1.5              .76
2017-03-30        2.3               .4
2017-03-31        1.2               1 

Here is the first and last part of the code I currently have:

df5=pd.DataFrame(columns=['Mean','Last'],index=index)
for item0 in y:
.........
.........
    df=df.rename(columns = {0:'Mean'})
    df4=pd.concat([df, df3], axis=1)
    print (df4)
    df5.append(df4)
    print (df5)

My code only puts one row into the dataframe like as opposed to a row for each item in y:

Index                Mean             Last
2017-03-29      1.5                .76