python - 在 Python 中使用 re.compile 函数逐行解析 gcode 文件

Question

我正在逐行解析一个 gcode 文件（位于 f_path 中），搜索给定的字符串。该字符串（“M622”）在整个文本文件中出现一个文本，其结构如下：

代码文件

M622; arm the Lasers
M610 S0 A80 B0 C0 ; allocate feeders
T0 ; set active extruder
G92 E0 ; set active extruder to 0
G28 XY ; home X and Y
G28 X ; home x
G90 ; absolute
G0 F3000 X35 Y5 S255 ; edge of plate
G92 X0 Y0 Z-2 ; local home
G0 Z0 ; drop Z 

最后，我希望代码返回找到字符串的行号。

代码

rgx_start = re.compile(r'M622') # String to be searched: "M622"
with open (f_path, 'rt') as txtfile:
    line = txtfile.readline()
    line_i = 0  # Counter of each line in the original text file
    hdr_start = 0 # Variable to store the line number where the header starts
    while line:  # Reading each line as a string
        while rgx_start.search(line) != None: # No "M622" is found => move to the next line
            line_i += 1 # The line counter is set to the next line
        hdr_start = line_i # When "M622" is found

print('First line: ',hdr_start)

当我运行上面的代码时，我进入了一个无限循环。有什么建议么？

Answer 1

你可以这样做：

import re
rgx_start = re.compile(r'M622') 
with open('gt.dat','r') as textfile:
   for i,line in enumerate(textfile.readlines()):
       if  rgx_start.search(line):
           line = i
           break  # since you said that it appears once
print(line)