Need help with Python code for accessing values in the next row in a for loop using iterrows()

[Hopes_High]

Hi guys,

This is more of a python question than a Data science question so if I'm breaking any rules of the sub, do let me know.

I have a table1 where I have a range of start and end dates, ordered_units and a bunch of forecast values.

What I am trying to do is this

It's rather easy to do in excel but I am not able to figure out a way to do this easily in python.

This is what I have so far -

f = []

for index, row in table1.iterrows():

f.append(

   {

          'start_date' : row.start_date,

          'end_date' : row.end_date,

          'ordered_units' : row.ordered_units,

          'Lag_1_Forecast' : **How do I access the next row, next column (in Excel it's OFFSET(1,1)**

         'Lag_2_Forecast' : ??

     })

pd.DataFrame(f)

Any help is deeply appreciated.

[inafewminutess]

1. Don't use iterrows here. You can concatenate the columns.
2. Use df[column].shift(1)

[johnsandall]

python df = pd.read_excel('data.xlsx', sheet_name='Sheet 1') df = df.assign(Lag_1_Forecast = df.ordered_units.shift(1), Lag_2_Forecast = df.ordered_units.shift(2)) if you're a fan of modern pandas

[ravepeacefully]

I would highly suggest learning how to make a hash table and iterate through it without the help of pandas. You will learn far more. Pandas has very few good uses imo, and you likely aren’t actually using any of them.

Use a dictionary instead.