在python中从具有不同行和列大小的文本文件中读取值

Question

我读过其他类似的文章，但在我看来它们似乎不起作用。 因此，我在这里新发布了它。

我有一个文本文件，其中的行和列大小都不同。 我对具有特定参数的值行感兴趣。 例如，在下面的示例文本文件中，我希望每行的最后两个值在第二个位置具有数字“ 1”。 也就是说，我希望从值“ 101至104”开始的行中使用值“ 1、101”，“ 101、2”，“ 2、102”和“ 102、3”，因为它们具有数字“ 1”在第二位置。

$MeshFormat
2.2 0 8
$EndMeshFormat
$Nodes
425
.
.
$EndNodes
$Elements
630
.
97 15 2 0 193 97
98 15 2 0 195 98
99 15 2 0 197 99
100 15 2 0 199 100
101 1 2 0 201 1 101
102 1 2 0 201 101 2
103 1 2 0 202 2 102
104 1 2 0 202 102 3
301 2 2 0 303 178 78 250
302 2 2 0 303 250 79 178
303 2 2 0 303 198 98 249
304 2 2 0 303 249 99 198
.
.
.
$EndElements

问题是，随着我下面提到的代码的出现，它从“ 101”开始，但是从其他行读取的值直到“ 304”或更多。 我做错了什么，或者有人可以更好地解决这个问题？

# Here, (additional_lines + anz_knoten_gmsh - 2) are additional lines that need to be skipped 
# at the beginning of the .txt file. Initially I find out where the range 
# of the lines lies which I need.
# The two_noded_elem_start is the first line having the '1' at the second position
# and four_noded_elem_start is the first line number having '2' in the second position. 
# So, basically I'm reading between these two parameters.


input_file = open(os.path.join(gmsh_path, "mesh_outer_region.msh"))
output_file = open(os.path.join(gmsh_path, "mesh_skip_nodes.txt"), "w")

for i, line in enumerate(input_file):                                                
    if i == (additional_lines + anz_knoten_gmsh + two_noded_elem_start - 2):         
        break

for i, line in enumerate(input_file):                                               
    if i == additional_lines + anz_knoten_gmsh + four_noded_elem_start - 2:         
        break

    elem_list = line.strip().split()                
    del elem_list[:5]                               
    writer = csv.writer(output_file)               
    writer.writerow(elem_list)                      

input_file.close()
output_file.close()

*编辑：用于查找诸如two_noded_elem_start之类的参数的代码段如下：

# anz_elemente_ueberg_gmsh is another parameter that is found out 
# from a previous piece of code and '$EndElements' is what 
# is at the end of the text file "mesh_outer_region.msh".

input_file = open(os.path.join(gmsh_path, "mesh_outer_region.msh"), "r")
for i, line in enumerate(input_file):                     
    if line.strip() == anz_elemente_ueberg_gmsh:
        break

for i, line in enumerate(input_file):                    
    if line.strip() == '$EndElements':                    
        break

    element_list = line.strip().split()                   
    if element_list[1] == '1':                            


        two_noded_elem_start = element_list[0]                       
        two_noded_elem_start = int(two_noded_elem_start)            
        break
input_file.close()

Answer 1

>>> with open('filename') as fh:             # Open the file
...    for line in fh:                       # For each line the file
...        values = line.split()             # Split the values into a list
...        if values[1] == '1':              # Compare the second value
...            print values[-2], values[-1]  # Print the 2nd from last and last
1 101
101 2
2 102
102 3