While loop doesn't send all line parameters before stopping thus finishes after second pass and sometimes directly after first pass.
i have tried reducing the number of steps but plays little difference
import requests
import rek #request script
import time
import pandas as pd
dfbig= pd.read_csv ('C:\\Users\\libraries2.csv')
step = 19
init = 0; final = init + step
while (final<= dfbig.shape[0]):
    df = dfbig.iloc [ init : final ]
    rek.req (df , init, final) 
    init = final
    final = init + step
    time.sleep (60)
It just stops before completing all lines of csv
 
     
    