Reading from a file and store the results in another file
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I have this code that reads a file and after processing a few lines writes the output to a second file:
num_reads = 7
with open('data.txt') as read_file:
with open('new_data.txt', 'w') as write_file:
while (True):
lines =
try: # expect errors if the number of lines in the file are not a multiplication of num_reads
for i in range(num_reads):
lines.append(next(read_file)) # when the file finishes an exception occurs here
#do sutff with the lines (exactly num_reads number of lines)
processed = " ".join(list(map(lambda x: x.replace("n", ''), lines)))
write_file.write(processed + 'n')
except StopIteration: # here we process the (possibly) insufficent last lines
#do stuff with the lines (less that num_reads)
processed = " ".join(list(map(lambda x: x.replace("n", ''), lines)))
write_file.write(processed + 'n')
break
Here is the input file (data.txt):
line1
line2
line3
line4
line5
line7
line8
line9
And this is the output file that has the desired state:
line1 line2 line3 line4 line5 line7
line8 line9
This works correctly but as I wish to do the same processing and writing procedure in both cases (when the number of elements is 7 and when the file finishes and the exception is raised) I think the above code violates DRY principle even if I define a new function and call it once in try block and once in except before break. Any other ordering that I could come up with was either causing an infinite loop or losing the final lines.
I appreciate any comments on handling this issue, as it is not limited to this case and I had faced it in other cases as well.
python error-handling
asked 1 hour ago
Farzad VertigoFarzad Vertigo
991
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Farzad Vertigo is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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add a comment |
$begingroup$
I have this code that reads a file and after processing a few lines writes the output to a second file:
num_reads = 7
with open('data.txt') as read_file:
with open('new_data.txt', 'w') as write_file:
while (True):
lines =
try: # expect errors if the number of lines in the file are not a multiplication of num_reads
for i in range(num_reads):
lines.append(next(read_file)) # when the file finishes an exception occurs here
#do sutff with the lines (exactly num_reads number of lines)
processed = " ".join(list(map(lambda x: x.replace("n", ''), lines)))
write_file.write(processed + 'n')
except StopIteration: # here we process the (possibly) insufficent last lines
#do stuff with the lines (less that num_reads)
processed = " ".join(list(map(lambda x: x.replace("n", ''), lines)))
write_file.write(processed + 'n')
break
Here is the input file (data.txt):
line1
line2
line3
line4
line5
line7
line8
line9
And this is the output file that has the desired state:
line1 line2 line3 line4 line5 line7
line8 line9
This works correctly but as I wish to do the same processing and writing procedure in both cases (when the number of elements is 7 and when the file finishes and the exception is raised) I think the above code violates DRY principle even if I define a new function and call it once in try block and once in except before break. Any other ordering that I could come up with was either causing an infinite loop or losing the final lines.
I appreciate any comments on handling this issue, as it is not limited to this case and I had faced it in other cases as well.
python error-handling
asked 1 hour ago
Farzad VertigoFarzad Vertigo
991
New contributor
Farzad Vertigo is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
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Welcome to Code Review! Please tell us in more detail what task this code accomplishes, ideally with example input and output files. Also retitle the question to state the purpose of the code, rather than your concern about the code. See How to Ask.
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– 200_success
23 mins ago
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@200_success done! :)
$endgroup$
– Farzad Vertigo
10 mins ago
add a comment |
$begingroup$
I have this code that reads a file and after processing a few lines writes the output to a second file:
num_reads = 7
with open('data.txt') as read_file:
with open('new_data.txt', 'w') as write_file:
while (True):
lines =
try: # expect errors if the number of lines in the file are not a multiplication of num_reads
for i in range(num_reads):
lines.append(next(read_file)) # when the file finishes an exception occurs here
#do sutff with the lines (exactly num_reads number of lines)
processed = " ".join(list(map(lambda x: x.replace("n", ''), lines)))
write_file.write(processed + 'n')
except StopIteration: # here we process the (possibly) insufficent last lines
#do stuff with the lines (less that num_reads)
processed = " ".join(list(map(lambda x: x.replace("n", ''), lines)))
write_file.write(processed + 'n')
break
Here is the input file (data.txt):
line1
line2
line3
line4
line5
line7
line8
line9
And this is the output file that has the desired state:
line1 line2 line3 line4 line5 line7
line8 line9
This works correctly but as I wish to do the same processing and writing procedure in both cases (when the number of elements is 7 and when the file finishes and the exception is raised) I think the above code violates DRY principle even if I define a new function and call it once in try block and once in except before break. Any other ordering that I could come up with was either causing an infinite loop or losing the final lines.
I appreciate any comments on handling this issue, as it is not limited to this case and I had faced it in other cases as well.
python error-handling
asked 1 hour ago
Farzad VertigoFarzad Vertigo
991
New contributor
Farzad Vertigo is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
I have this code that reads a file and after processing a few lines writes the output to a second file:
num_reads = 7
with open('data.txt') as read_file:
with open('new_data.txt', 'w') as write_file:
while (True):
lines =
try: # expect errors if the number of lines in the file are not a multiplication of num_reads
for i in range(num_reads):
lines.append(next(read_file)) # when the file finishes an exception occurs here
#do sutff with the lines (exactly num_reads number of lines)
processed = " ".join(list(map(lambda x: x.replace("n", ''), lines)))
write_file.write(processed + 'n')
except StopIteration: # here we process the (possibly) insufficent last lines
#do stuff with the lines (less that num_reads)
processed = " ".join(list(map(lambda x: x.replace("n", ''), lines)))
write_file.write(processed + 'n')
break
Here is the input file (data.txt):
line1
line2
line3
line4
line5
line7
line8
line9
And this is the output file that has the desired state:
line1 line2 line3 line4 line5 line7
line8 line9
This works correctly but as I wish to do the same processing and writing procedure in both cases (when the number of elements is 7 and when the file finishes and the exception is raised) I think the above code violates DRY principle even if I define a new function and call it once in try block and once in except before break. Any other ordering that I could come up with was either causing an infinite loop or losing the final lines.
I appreciate any comments on handling this issue, as it is not limited to this case and I had faced it in other cases as well.
python error-handling
python error-handling
asked 1 hour ago
Farzad VertigoFarzad Vertigo
991
New contributor
Farzad Vertigo is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 1 hour ago
Farzad VertigoFarzad Vertigo
991
New contributor
Farzad Vertigo is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 11 mins ago
Farzad Vertigo
asked 1 hour ago
Farzad VertigoFarzad Vertigo
991
New contributor
Farzad Vertigo is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 1 hour ago
Farzad VertigoFarzad Vertigo
991
asked 1 hour ago
Farzad VertigoFarzad Vertigo
991
991
New contributor
Farzad Vertigo is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Farzad Vertigo is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Farzad Vertigo is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
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Welcome to Code Review! Please tell us in more detail what task this code accomplishes, ideally with example input and output files. Also retitle the question to state the purpose of the code, rather than your concern about the code. See How to Ask.
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– 200_success
23 mins ago
$begingroup$
@200_success done! :)
$endgroup$
– Farzad Vertigo
10 mins ago
add a comment |
$begingroup$
Welcome to Code Review! Please tell us in more detail what task this code accomplishes, ideally with example input and output files. Also retitle the question to state the purpose of the code, rather than your concern about the code. See How to Ask.
$endgroup$
– 200_success
23 mins ago
$begingroup$
@200_success done! :)
$endgroup$
– Farzad Vertigo
10 mins ago
$begingroup$
Welcome to Code Review! Please tell us in more detail what task this code accomplishes, ideally with example input and output files. Also retitle the question to state the purpose of the code, rather than your concern about the code. See How to Ask.
$endgroup$
– 200_success
23 mins ago
$begingroup$
Welcome to Code Review! Please tell us in more detail what task this code accomplishes, ideally with example input and output files. Also retitle the question to state the purpose of the code, rather than your concern about the code. See How to Ask.
$endgroup$
– 200_success
23 mins ago
$begingroup$
@200_success done! :)
$endgroup$
– Farzad Vertigo
10 mins ago
$begingroup$
@200_success done! :)
$endgroup$
– Farzad Vertigo
10 mins ago
add a comment |
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Farzad Vertigo is a new contributor. Be nice, and check out our Code of Conduct.
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Welcome to Code Review! Please tell us in more detail what task this code accomplishes, ideally with example input and output files. Also retitle the question to state the purpose of the code, rather than your concern about the code. See How to Ask.
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– 200_success
23 mins ago
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@200_success done! :)
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– Farzad Vertigo
10 mins ago