How can I see the formulas of an excel spreadsheet in pandas / python?

Yes, it is possible. I recently found a package that solves this issue in a quite sophisticated way. It is called portable-spreadsheet (available via pip install portable-spreadsheet). It basically encapsulates xlsxwriter. Here is a simple example:

import portable_spreadsheet as ps
sheet = ps.Spreadsheet.create_new_sheet(5, 5)
# Set values
sheet.iloc[0, 0] = 25  # Set A1
sheet.iloc[1, 0] = sheet.iloc[0, 0]  # reference to A1
# Export to Excel
sheet.to_excel('output/sample.xlsx')

It works in a similar way as Pandas Dataframe.

OpenPyXL provides this capacity out-of-the-box. See here and here. An example:

from openpyxl import load_workbook
import pandas as pd
wb = load_workbook(filename = 'empty_book.xlsx')
sheet_names = wb.get_sheet_names()
name = sheet_names[0]
sheet_ranges = wb[name]
df = pd.DataFrame(sheet_ranges.values)