Using pandas, index error

[fyec]

I am trying to round numbers, if their decimal numbers end with (125, 375, 625, 875), I replace them with (25, 25, 75, 75). My code is:

import pandas as pd  

inpExcelFile = 'Lat Lon Coordinates and soil.csv'  #lat, lon
gridCells = pd.read_csv(inpExcelFile)
#inpExcelFile can be downloaded from "http://www.evernote.com/l/AWMD9Le15ytJmokhnUF8r84vtXVIsj2_lBQ/"

df = pd.DataFrame(columns=['lat_ext', 'lon_ext', 'lat_close', 'lon_close'])

for i in range(0, len(gridCells.index)):  

    if str(df.at[i, 'lat_ext'])== str('125'):
       df.at[i, 'lat_close'] =  float((str(gridCells.at[i, 'lat'])[:3]) + str('25'))
    if str(df.at[i, 'lat_ext'])== str('375'):
       df.at[i, 'lat_close'] = float((str(gridCells.at[i, 'lat'])[:3]) + str('25'))
    if str(df.at[i, 'lat_ext'])== str('625'):
       df.at[i, 'lat_close'] = float((str(gridCells.at[i, 'lat'])[:3]) + str('75'))
    if str(df.at[i, 'lat_ext'])== str('875'):
       df.at[i, 'lat_close'] = float((str(gridCells.at[i, 'lat'])[:3]) + str('75'))

for j in range(0, len(gridCells.index)):  

    if str(df.at[j, 'lon_ext'])== str('125'):
       df.at[j, 'lon_close'] =  float((str(gridCells.at[j, 'lat'])[:3]) + str('25'))
    if str(df.at[j, 'lon_ext'])== str('375'):
       df.at[j, 'lon_close'] = float((str(gridCells.at[j, 'lat'])[:3]) + str('25'))
    if str(df.at[j, 'lon_ext'])== str('625'):
       df.at[j, 'lon_close'] = float((str(gridCells.at[j, 'lat'])[:3]) + str('75'))
    if str(df.at[j, 'lon_ext'])== str('875'):
       df.at[j, 'lon_close'] = float((str(gridCells.at[j, 'lat'])[:3]) + str('75'))

df.to_excel('cikti' + '.xlsx')

I am getting this error:

Error:
  File "<ipython-input-1-eff718b7025b>", line 1, in <module>
    runfile('C:/Users/fyunu/OneDrive/Masaüstü/code rubbish/untitled3.py', wdir='C:/Users/fyunu/OneDrive/Masaüstü/code rubbish')

  File "C:\Users\fyunu\Anaconda3\lib\site-packages\spyder\utils\site\sitecustomize.py", line 705, in runfile
    execfile(filename, namespace)

  File "C:\Users\fyunu\Anaconda3\lib\site-packages\spyder\utils\site\sitecustomize.py", line 102, in execfile
    exec(compile(f.read(), filename, 'exec'), namespace)

  File "C:/Users/fyunu/OneDrive/Masaüstü/code rubbish/untitled3.py", line 20, in <module>
    if str(df.at[i, 'lat_ext'])== str('125'):

  File "C:\Users\fyunu\Anaconda3\lib\site-packages\pandas\core\indexing.py", line 2141, in __getitem__
    key = self._convert_key(key)

  File "C:\Users\fyunu\Anaconda3\lib\site-packages\pandas\core\indexing.py", line 2227, in _convert_key
    raise ValueError("At based indexing on an non-integer "

ValueError: At based indexing on an non-integer index can only have non-integer indexers

How can I solve that problem?

[volcano63]

Disregarding the fact that this is misuse of pandas API, your df is empty - so applying df.at cannot yield any result