有條件地導入文本文件中的行

Question

我有一個代碼，我在這裏導入文本文件的內容並做一些繪圖。我的要求是，我想通過給出條件只導入那些行數據。在對導入的數據進行一些計算之後，我想要導入文本文件中剩餘的其餘行並進行進一步計算。這個過程完成後，我想分別將兩個計算組合成兩個數組。

這是我有的示例代碼。我也上傳了文本文件到保管箱中。

import numpy as np 
from matplotlib import pyplot as plt 
from scipy.interpolate import RectBivariateSpline 
import numdifftools as nd 
plt.ioff() 

data5= np.loadtxt('textfile',skiprows=1,unpack = True).T 
ts3 = data5[:,1] ## Condition based on this data 
fillend= 37900 ## Read rows only till this value 
ft3 = data5[:,0] 
t3 = data5[:,2] 
Ek3 = data5[:,13] 
ek3 = data5[:,14] 
eko3 = data5[:,15] 
Eko3 = data5[:,16] 

## Initially I want to read only all the rows until ts3=37900 with the row corresponding to fillend also included 
## Until ts3 =37900, this is the calculation that I want to make 

e2 = interpolate.InterpolatedUnivariateSpline(t2,Ek2,k=5) ## Here length of Ek2 and t2 should be equal to 378) 

df2 =nd.Derivative(e2,method='central',n=1,order=2,full_output=False) 
e2 = (1-df2(t2)) 
df2 = df2(t2) 

## Beyond ts3 = 37900, i.e from 38000 onwards, this is the calculation that I want to make 
df2 =nd.Derivative(e2,method='central',n=1,order=2,full_output=False) 
e2 = (-df2(t2)) 
df2 = df2(t2) 

## At the end of the operation, I want to have only two arrays e2 and df2 with all the values calculated 

Sample file

Answer 1

這裏的加載TXT的一個簡單的例子（線）中兩個塊的基礎上，在所述線的值。我正在模擬一個帶有字符串列表的文件。 foo是一個生成器函數，它返回2個塊中的輸入。

import numpy as np 

t0 = '1, 2, 3, 4' 
t1 = '4, 5, 6, 7' 
txt=[t0,t0,t0,t1,t1,t1] 

def foo(txt): 
    lines = [] 
    while txt: 
     l = txt.pop(0) 
     if int(l.split(',')[1])<4: lines.append(l) 
     else: 
      yield lines 
      break 
    yield [l]+txt 

for lines in foo(txt[:]): 
    print(np.loadtxt(lines, delimiter=',')) 

結果是2個數組：

2033:~/mypy$ python stack36001473.py 
[[ 1. 2. 3. 4.] 
[ 1. 2. 3. 4.] 
[ 1. 2. 3. 4.]] 
[[ 4. 5. 6. 7.] 
[ 4. 5. 6. 7.] 
[ 4. 5. 6. 7.]]