how can i sum first day value of each id together? I have a data frame like this:

 id                 Date       Volume      Price     Values(Volume*Price)
56033738624803469  20170111    1          943339    943339
56033738624803469  20170111    10         919410    9194100
56033738624803469  20170112    1          919410    919410
56033738624803469  20170112    5          954999    4774955
4659957480182399   20170207    1          1000000   1000000
4659957480182399   20170208    5          1000000   5000000
4659957480182399   20170208    40         1000000   40000000


I want to compute and plot the following computation for the first 100 days for each ID:

compute average values per day over the first 100 days
Plot this for all of Ids
Afterwards, the plot should like this:
Desired plot (https://i.stack.imgur.com/2cozR.png)

This is what I've done so far:

df2 = df.groupby(['Id', 'Date']).sum()


The result is :

                           Index   Volume        Price        Values
Id               Date                                               
1745829084228393 20170207      1     1000    1000000.0  1.000000e+09
                 20170208   5151   999000  101000000.0  9.990000e+11 
                 20170403      1       12    1000100.0  1.200120e+07
                 20170408      1       12    1000000.0  1.200000e+07
                 20170417      1      500    1000000.0  5.000000e+08
                 20170423      3    14500    2000000.0  1.450000e+10
                 20170507     10    35000    4000000.0  3.500000e+10
                 20170510     21    49051    6000000.0  4.905100e+10
                 20170529      1        4    1000000.0  4.000000e+06
2888358730233310 20170212    820  2000000   40000000.0  2.000000e+12
2929948497881810 20170207   1830  1500000   60000000.0  1.500000e+12
                 20170208    903   700000   42000000.0  7.000000e+11
                 20170212   1176   800000   48000000.0  8.000000e+11
3715246194918044 20150509     66     1008   11000000.0  1.008000e+09


Now I want to calculate sum of first , second ,... of each ID for Values, for example:

 Date_Order     Sum_Values(= summation first date of each id )

 first_Date     (1.000000e+09 + 2.000000e+12 + 1.500000e+12 + 1.008000e+09)

 second_Date    (9.990000e+11 + 7.000000e+11)


ids are important i want summation of first day of values of each id(ids are different and may start on different days)
Just a suggestion:

Let the length of the most transaction over all ID be $n$.

Prepare a list of size $n$, $A$, initialize all entries to $0$.

Now go through each ID, suppose a particular ID has $m$ transaction.  We add the value of the $i$-th transaction to the $i$-th entry of $A$.

The list $A$ would have your desired information. The $i$-entry stores the sum of values of the $i$-th day.

Alternatively, you can also introduce a new feature that encode which transaction  is it for each ID and then use groupby to sum it up again.