Raw output data frame manipulation in python - python-3.x

Question

Using python 3 I need to process qPCR sequencing raw data outputs by searching for the first occurrence of a user defined string and then making a new data frame using all lines after that string. I am trying to find solutions in the pandas doc but so far unsuccessful.
This is a raw output .csv file that I need to process. (couldn't paste complete csv as exceeds character limit, this is lines 40-50 and am hoping this text is useful?). I need to tell pandas to create a new data frame that 1. starts at the line containg the first occurance of str("Sample Name") with that line as header and containing all lines following. And then 2., only including columns ("Sample Name"), ("Target Name"), ("CT").
Could someone please help me so that I can use python to help me analyze biological data?
Many thanks,
Luke
40,Quantification Cycle Method,Ct,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
41,Signal Smoothing On,true,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
42,Stage where Melt Analysis is performed,Stage3,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
43,Stage/ Cycle where Ct Analysis is performed,"Stage2, Step2",,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
44,User Name,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
45,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
46,Well,Well Position,Omit,Sample Name,Target Name,Task,Reporter,Quencher,Quantity,Quantity Mean,SE,RQ,RQ Min,RQ Max,CT,Ct Mean,Ct SD,Delta Ct,Delta Ct Mean,Delta Ct SD,Delta Ct SE,Delta Delta Ct,Automatic Ct Threshold,Ct Threshold,Automatic Baseline,Baseline Start,Baseline End,Amp Status,Comments,Cq Conf,CQCONF,HIGHSD,OUTLIERRG,Tm1,Tm2,Tm3,Tm4
47,1,A1,False,WT1,AtTubulin,UNKNOWN,SYBR,None,,,,,,,23.357698440551758,23.4766845703125,0.5336655378341675,,,,,,True,20959.612776965325,True,3,17,Amp,,0.9588544573203085,N,Y,N,81.40960693359375,,,
48,2,A2,False,WT1,AtTubulin,UNKNOWN,SYBR,None,,,,,,,24.05980110168457,23.4766845703125,0.5336655378341675,,,,,,True,20959.612776965325,True,3,15,Amp,,0.9592687354496955,N,Y,N,81.40960693359375,,,
49,3,A3,False,WT1,AtTubulin,UNKNOWN,SYBR,None,,,,,,,23.012556076049805,23.4766845703125,0.5336655378341675,,,,,,True,20959.612776965325,True,3,16,Amp,,0.9592714462250367,N,Y,N,81.40960693359375,,,
50,4,A4,False,fla11fla12-1,AtTubulin,UNKNOWN,SYBR,None,,,,,,,23.803699493408203,24.419523239135742,0.5669151544570923,,,,,,True,20959.612776965325,True,3,17,Amp,,0.9671570584141241,N,Y,N,81.40960693359375,,,
This is the code that I have so far:
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
data = pd.read_excel ("2019-02-27_161601 AtWAKL8 different version expressions.xls", sheet_name='Results').fillna(0)
data.to_csv('df1' + '.csv', index=True)
df1 = pd.read_csv ("df1.csv")

Answer 1

You are having trouble with quoting.
grep is a better fit for .csv files rather than .xlsx
You are forking off a shell subprocess with a filename argument,
without correctly quoting the spaces in the filename.
It would be simplest to rename it, turning spaces into dashes,
e.g. 2019-02-27_161601-AtWAKL8-different-version-expressions.xls
As it stands, you are trying to grep the string "Position"
from a file named 2019-02-27_161601,
and from a 2nd file named AtWAKL8,
a 3rd named different, and so on,
which is unlikely to work.
An .xlsx spreadsheet is not the line-oriented
text format that grep expects.
You will be happier if you export or Save As .csv format within Excel,
or if you execute data.to_csv('expressions.csv')