I'm new to python and I just started learning the basics.
I'm trying to create a program that will take a file and comment (using # ) the lines that don't have anything after the equal sign.
For example,
V12 =
V13 = 3
Should be
#V12 =
V13 = 3
Thank you in advance for your help.
Essentially, you'll need to read in the file. Then, check each line. If the line has something after you split on the equal sign, just output the line as is; otherwise, append a hashtag to the front and then output the line.
f = open(filename, "r")
lines = f.readlines()
f.close()
output_lines = []
for line in lines:
if len(line.split("=")[1]) > 0:
output_lines.append(line)
else:
output_lines.append("#" + line)
f = open("commented" + filename, "w")
f.write("\n".join(output_lines))
f.close()
For something like this I would keep it simple and read from one file and write to another.
with open('/path/to/myfile') as infile:
with open('/path/to/output', 'w') as outfile:
for line in infile:
if line.rstrip().endswith('='):
outfile.write('#' + line + '\n')
else:
outfile.write(line + '\n')
Here is some code that you can run like:
python comment.py < infile > outfile
comment.py:
import sys
# stdin/stdout live in sys
# "for line in file" reads each line of the file, returning the text
# of the line including the trailing newline
for line in sys.stdin:
if line.strip().endswith('='):
line = "#" + line
# print command adds a trailing newline, so we have to use all but
# the last character of our input line
print(line[:-1])
You can get a lot fancier using the re module for regular expressions.
Given infile:
V12 = 'hello'
V23 = 'world'
V34 =
produces:
V12 = 'hello'
V23 = 'world'
#V34 =
You could also use this code to accomplish your task. The only restriction is that the empty variable is identified by no whitespace. E.g. 'v1='
MyFile=open("AFile.txt", 'r+');
newdata = []
data = MyFile.readlines()
for item in data:
PosEquals = item.find('=')
LenOfItem = len(item)
# Checks position of equals in line
# and also if there is anything after equal sign
if PosEquals <> -1 and PosEquals <> LenOfItem-1:
newdata.append(item)
else:
newdata.append('#'+item)
MyFile.seek(0)
MyFile.writelines(newdata)
MyFile.close()
