读取“重复”文件的特定位置

Question

我想读一本书文件.txt在python中，然后打印一个特定的位置，我有两方的“轨道能量”，但我只对最后一方感兴趣，特别是，对应于2.0000和0.0000的线。这里的输入文件是：

------------轨道能量------------------

NO   OCC          E(Eh)            E(eV)     
0   2.0000    -19.126728        -520.4647     
1   2.0000      -1.009435       -27.4681     
2   2.0000      -0.538078       -14.6418     
3   2.0000      -0.388855       -10.5813     
4   2.0000      -0.321100        -8.7376     
5   0.0000      -0.008155        -0.2219     
6   0.0000       0.044286         1.2051     
7   0.0000       0.141342         3.8461     
8   0.0000       0.144536         3.9330     
9   0.0000       0.153520         4.1775    
10   0.0000       0.168115         4.5746    

---------------- ORBITAL ENERGIES ----------------

NO   OCC          E(Eh)            E(eV)     
0   2.0000      -19.127397      -520.4829     
1   2.0000      -1.014381       -27.6027     
2   2.0000      -0.530762       -14.4428     
3   2.0000      -0.398228       -10.8363     
4   2.0000      -0.322062        -8.7638     
5   0.0000      -0.007625        -0.2075     
6   0.0000       0.044967         1.2236     
7   0.0000       0.140524         3.8238     
8   0.0000       0.144488         3.9317     
9   0.0000       0.157663         4.2902    
10   0.0000       0.166347         4.5265    
11   0.0000       0.221116         6.0169  

我用了这个代码：

#!/usr/bin/env python



import sys, os



# ------------- GET INPUT FILE ------------- #  
if len(sys.argv) <= 1:
  name = raw_input("Enter path to input: ")
else:
  name = sys.argv[1] 

fo = open(name, "r")


lines = fo.readlines()
fo.close()




# ------------------------------------------ #

# Define Variables 
omega = 0
o_HOMO = []
o_LUMO = []



# Sort Input Into Lists
for line in lines:
  line = line.split() # split lines into lists
  if not line: # skip empty lines
    continue
  if len(line) >= 3:
    if line[1] == '2.0000': # gather neutral occupied eigenvalues (if closed shell)
      o_HOMO.append(line[3])
    elif line[1] == '0.0000': # gather virtual orbitals
      o_LUMO.append(line[3])





for idx, item in enumerate(o_HOMO):        #HOMO
  if idx == len(o_HOMO) - 1:
    print(item)



for idx, item in enumerate(o_LUMO):        #LUMO
  if idx == len(o_LUMO) - 1:
    print(item)

我的结果是这样的：

零下8.7638

6.0169年

但我想要这样的结果：

零下8.7638

-0.2075年

Answer 1

使用Python 3的解决方案：

zero_flag = 0
two_val = 0
zero_val = 0    
with open("data.txt","r") as fp:
    line_list = fp.readlines()
    middle_str = "         ORBITAL ENERGIES         \n"
    pos = len(line_list) - line_list[::-1].index(middle_str) - 1
    line_list = line_list[pos:]
    line_list = [line.strip() for line in line_list if line.strip()!=""]
    for line in line_list:
        try:
            ar = list(map(float,line.split()))
            if ar[1] == 2:
                two_val = ar[3]
            if ar[1] == 0 and zero_flag == 0:
                zero_val = ar[3]
                zero_flag = 1
        except:
            pass
print(two_val)
print(zero_val)

输出：

-8.7638
-0.2075

Data.txt文件包含：

         ORBITAL ENERGIES         

NO   OCC          E(Eh)            E(eV)     
0   2.0000    -19.126728        -520.4647     
1   2.0000      -1.009435       -27.4681     
2   2.0000      -0.538078       -14.6418     
3   2.0000      -0.388855       -10.5813     
4   2.0000      -0.321100        -8.7376     
5   0.0000      -0.008155        -0.2219     
6   0.0000       0.044286         1.2051     
7   0.0000       0.141342         3.8461     
8   0.0000       0.144536         3.9330     
9   0.0000       0.153520         4.1775    
10   0.0000       0.168115         4.5746    

         ORBITAL ENERGIES         

NO   OCC          E(Eh)            E(eV)     
0   2.0000      -19.127397      -520.4829     
1   2.0000      -1.014381       -27.6027     
2   2.0000      -0.530762       -14.4428     
3   2.0000      -0.398228       -10.8363     
4   2.0000      -0.322062        -8.7638     
5   0.0000      -0.007625        -0.2075     
6   0.0000       0.044967         1.2236     
7   0.0000       0.140524         3.8238     
8   0.0000       0.144488         3.9317     
9   0.0000       0.157663         4.2902    
10   0.0000       0.166347         4.5265    
11   0.0000       0.221116         6.0169

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