Python-UV-vis data processing

# !/usr/bin/env python
#  -*- coding: utf-8 -*-
# Author:
# Date:2020.10.13   23:31
import tkinter as tk
from tkinter.filedialog import askopenfilename
from itertools import islice
import sys
import fileinput
import matplotlib.pylab as pylab
#import numpy as np
#import matplotlib.pyplot as plt
data_file_path = askopenfilename(title='Select a data',filetypes=[('TXT','*.txt')],initialdir='E:\\00Experiment\\20201013')
print(data_file_path)
#f1 = open(data_file_path,'r')
#E:\00 Experiment\20201013
#islice(seq[, start], stop[, step]);返回序列seq的从start开始到stop结束的步长为step的元素的迭代器
from itertools import islice
#with open(r'E:\\00Experiment\\movie2.txt', encoding='utf-8', ) as txtfile:
data=[]
with open(data_file_path ) as txtfile:
    line = txtfile.readlines()
    for i, rows in enumerate(line):
        if i in range(58, len(line)-1):  # 指定数据行
            #print(rows)
            data.append(rows)
print("length", len(data))
txtfile.close()
# #写入
with open('E:\\00Experiment\\movie2.txt', "w", ) as f:
    for i in range(len(data)):
        f.writelines(data[i])
    f.close()
x = []
y = []
with open('E:\\00Experiment\\movie2.txt', "r", ) as f2:
        
    for line in f2:
        trainingset = line.split('\t', 1 )    
        x.append(trainingset[0])   
        #print(x)
        y.append(trainingset[1])  
length = len(y)
pylab.figure(1)
pylab.plot(x, y, 'r-')
pylab.xlabel('time')
pylab.ylabel('amplitude')
pylab.show() 

#http://www.360doc.com/content/19/0828/10/47812380_857519286.shtml