Read/write a pipe-delimited file line by line with some simple text manipulationRead file line-by-line with circular bufferRead Space Delimited Text File to Standardized Data Typefunction responsible for parsing 2 csv txt files, comparing them and writing csv txt files as outputC++ Read File line by lineA minimal CLI password storage and retrieval managerPython read/write pickled fileSimple python code takes command line argument for file location and tokenizes textRead integers from text file and write to CSV fileFile manipulation with HaskellRead and write BMP file in C
How can saying a song's name be a copyright violation?
In a Spin are Both Wings Stalled?
Does casting Light, or a similar spell, have any effect when the caster is swallowed by a monster?
90's TV series where a boy goes to another dimension through portal near power lines
Why is Collection not simply treated as Collection<?>
Why do I get two different answers for this counting problem?
If human space travel is limited by the G force vulnerability, is there a way to counter G forces?
Where does SFDX store details about scratch orgs?
Fully-Firstable Anagram Sets
I Accidentally Deleted a Stock Terminal Theme
What's the difference between 'rename' and 'mv'?
Is "remove commented out code" correct English?
I'm flying to France today and my passport expires in less than 2 months
Python: return float 1.0 as int 1 but float 1.5 as float 1.5
Can I use a neutral wire from another outlet to repair a broken neutral?
How to take photos in burst mode, without vibration?
How do I write bicross product symbols in latex?
Theorems that impeded progress
1960's book about a plague that kills all white people
Has there ever been an airliner design involving reducing generator load by installing solar panels?
UK: Is there precedent for the governments e-petition site changing the direction of a government decision?
Did converts (ger tzedek) in ancient Israel own land?
Is it unprofessional to ask if a job posting on GlassDoor is real?
Will google still index a page if I use a $_SESSION variable?
Read/write a pipe-delimited file line by line with some simple text manipulation
Read file line-by-line with circular bufferRead Space Delimited Text File to Standardized Data Typefunction responsible for parsing 2 csv txt files, comparing them and writing csv txt files as outputC++ Read File line by lineA minimal CLI password storage and retrieval managerPython read/write pickled fileSimple python code takes command line argument for file location and tokenizes textRead integers from text file and write to CSV fileFile manipulation with HaskellRead and write BMP file in C
.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty margin-bottom:0;
$begingroup$
This code that I wrote is supposed to read/write a pipe-delimited file line by line to a new file with some simple text manipulation. (It also adds two new columns) and publishes a "Status Update" ever 100,000 lines to keep me updated on how close it is to completion.
I previously posted this code on StackOverflow to get help with incrementing, and someone mentioned that it would be faster if I did not open the second text file, but being extremely new at Python, I do not understand how to do that without potentially breaking the code.
counter=1
for line in open(r"C:Pathname.txt"):
spline = line.split("|")
if counter==1:
with open(r"C:PATH2019.txt",'a') as NewFile:
spline.insert(23,"Column A")
spline.insert(23,"Column B")
s="|"
newline=s.join(spline)
NewFile.write(newline)
elif counter > 1 and not spline[22]=="0.00":
spline.insert(23,"")
spline.insert(23,"")
gl=spline[0]
gl=gl.strip()
if gl[0]=="-": gl="000" + gl
gl=gl.upper()
spline[0]=gl
if gl[:3]=="000": spline[24]="Incorrect"
s="|"
newline=s.join(spline)
with open(r"C:PATHPythonWrittenData.txt",'a') as NewFile:
NewFile.write(newline)
counter+=1
if counter%100000==0: print("Status Update: n", ":,".format(counter))
python beginner python-3.x file csv
$endgroup$
add a comment |
$begingroup$
This code that I wrote is supposed to read/write a pipe-delimited file line by line to a new file with some simple text manipulation. (It also adds two new columns) and publishes a "Status Update" ever 100,000 lines to keep me updated on how close it is to completion.
I previously posted this code on StackOverflow to get help with incrementing, and someone mentioned that it would be faster if I did not open the second text file, but being extremely new at Python, I do not understand how to do that without potentially breaking the code.
counter=1
for line in open(r"C:Pathname.txt"):
spline = line.split("|")
if counter==1:
with open(r"C:PATH2019.txt",'a') as NewFile:
spline.insert(23,"Column A")
spline.insert(23,"Column B")
s="|"
newline=s.join(spline)
NewFile.write(newline)
elif counter > 1 and not spline[22]=="0.00":
spline.insert(23,"")
spline.insert(23,"")
gl=spline[0]
gl=gl.strip()
if gl[0]=="-": gl="000" + gl
gl=gl.upper()
spline[0]=gl
if gl[:3]=="000": spline[24]="Incorrect"
s="|"
newline=s.join(spline)
with open(r"C:PATHPythonWrittenData.txt",'a') as NewFile:
NewFile.write(newline)
counter+=1
if counter%100000==0: print("Status Update: n", ":,".format(counter))
python beginner python-3.x file csv
$endgroup$
$begingroup$
Can you edit your question to explain what the loop is supposed to do?
$endgroup$
– David White
Apr 1 at 14:28
$begingroup$
@DavidWhite Added. For quick reference: It reads one text file line by line, performs string manipulation, and then writes it into a new file line by line.
$endgroup$
– Emily Alden
Apr 1 at 14:56
add a comment |
$begingroup$
This code that I wrote is supposed to read/write a pipe-delimited file line by line to a new file with some simple text manipulation. (It also adds two new columns) and publishes a "Status Update" ever 100,000 lines to keep me updated on how close it is to completion.
I previously posted this code on StackOverflow to get help with incrementing, and someone mentioned that it would be faster if I did not open the second text file, but being extremely new at Python, I do not understand how to do that without potentially breaking the code.
counter=1
for line in open(r"C:Pathname.txt"):
spline = line.split("|")
if counter==1:
with open(r"C:PATH2019.txt",'a') as NewFile:
spline.insert(23,"Column A")
spline.insert(23,"Column B")
s="|"
newline=s.join(spline)
NewFile.write(newline)
elif counter > 1 and not spline[22]=="0.00":
spline.insert(23,"")
spline.insert(23,"")
gl=spline[0]
gl=gl.strip()
if gl[0]=="-": gl="000" + gl
gl=gl.upper()
spline[0]=gl
if gl[:3]=="000": spline[24]="Incorrect"
s="|"
newline=s.join(spline)
with open(r"C:PATHPythonWrittenData.txt",'a') as NewFile:
NewFile.write(newline)
counter+=1
if counter%100000==0: print("Status Update: n", ":,".format(counter))
python beginner python-3.x file csv
$endgroup$
This code that I wrote is supposed to read/write a pipe-delimited file line by line to a new file with some simple text manipulation. (It also adds two new columns) and publishes a "Status Update" ever 100,000 lines to keep me updated on how close it is to completion.
I previously posted this code on StackOverflow to get help with incrementing, and someone mentioned that it would be faster if I did not open the second text file, but being extremely new at Python, I do not understand how to do that without potentially breaking the code.
counter=1
for line in open(r"C:Pathname.txt"):
spline = line.split("|")
if counter==1:
with open(r"C:PATH2019.txt",'a') as NewFile:
spline.insert(23,"Column A")
spline.insert(23,"Column B")
s="|"
newline=s.join(spline)
NewFile.write(newline)
elif counter > 1 and not spline[22]=="0.00":
spline.insert(23,"")
spline.insert(23,"")
gl=spline[0]
gl=gl.strip()
if gl[0]=="-": gl="000" + gl
gl=gl.upper()
spline[0]=gl
if gl[:3]=="000": spline[24]="Incorrect"
s="|"
newline=s.join(spline)
with open(r"C:PATHPythonWrittenData.txt",'a') as NewFile:
NewFile.write(newline)
counter+=1
if counter%100000==0: print("Status Update: n", ":,".format(counter))
python beginner python-3.x file csv
python beginner python-3.x file csv
edited Apr 1 at 16:48
200_success
131k17157422
131k17157422
asked Apr 1 at 13:23
Emily AldenEmily Alden
24228
24228
$begingroup$
Can you edit your question to explain what the loop is supposed to do?
$endgroup$
– David White
Apr 1 at 14:28
$begingroup$
@DavidWhite Added. For quick reference: It reads one text file line by line, performs string manipulation, and then writes it into a new file line by line.
$endgroup$
– Emily Alden
Apr 1 at 14:56
add a comment |
$begingroup$
Can you edit your question to explain what the loop is supposed to do?
$endgroup$
– David White
Apr 1 at 14:28
$begingroup$
@DavidWhite Added. For quick reference: It reads one text file line by line, performs string manipulation, and then writes it into a new file line by line.
$endgroup$
– Emily Alden
Apr 1 at 14:56
$begingroup$
Can you edit your question to explain what the loop is supposed to do?
$endgroup$
– David White
Apr 1 at 14:28
$begingroup$
Can you edit your question to explain what the loop is supposed to do?
$endgroup$
– David White
Apr 1 at 14:28
$begingroup$
@DavidWhite Added. For quick reference: It reads one text file line by line, performs string manipulation, and then writes it into a new file line by line.
$endgroup$
– Emily Alden
Apr 1 at 14:56
$begingroup$
@DavidWhite Added. For quick reference: It reads one text file line by line, performs string manipulation, and then writes it into a new file line by line.
$endgroup$
– Emily Alden
Apr 1 at 14:56
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
A nice trick you can use in python is to open two (or more) files at once in one line. This is done with something like:
with open('file_one.txt', 'r') as file_one, open('file_two.txt', 'r') as file_two:
for line in file_one:
...
for line in file_two:
...
This is a very common way of reading from one file and writing to another without continually opening and closing one of them.
Currently, you're opening and closing the files with each iteration of the loop. Your program loops through the lines in name.txt
, checks an if
/ elif
condition, then if either are satisfied, a file is opened, written to, then closed again with every iteration of the loop.
Simply by opening both files at the same time you can stop opening and closing them repeatedly.
For more info on the with
statement and other context managers, see here.
Another small improvement can be made. At the moment, you check the first if
condition every time, but you know it will only actually evaluate to True
once. it would be better to remove that check and just always perform that block once. Assign counter after the first block (after where if counter == 1
currently is) then replace the elif
statement with a while
loop.
It would be worth getting familiar with PEP8 if you're going to use Python a lot in the future. It's a standard style guide and will help with the readability of your code (for you and others). Just small stuff like new lines after colons or spaces either side of variable declarations / comparisons.
If you include an example file and desired output, there may be more I can help with.
$endgroup$
$begingroup$
I decided to accept this answer as it has the information most pertinent to my skill level and it worked. (I couldn't get the iterative answer to produce the expected results). Thank you very much. I am modifying my code so that it will be PEP8 compliant.
$endgroup$
– Emily Alden
Apr 1 at 21:07
add a comment |
$begingroup$
Here is another way to organize your code. Instead of an if
within the loop, use iterators more explicitly. Concretely:
with open(r"C:Pathname.txt") as source:
lines = iter(source)
# first line
first_line = next(lines)
with open(r"C:PATH2019.txt") as summary:
# ... omitted ...
# remaining lines
with open(r"C:PATHPythonWrittenData.txt", 'a') as dest:
for counter, line in enumerate(lines, start=1):
# ... omitted ...
I have also used enumerate
to update counter
and line
simultaneously.
The other answer has some more tips on writing good python code. But as far as structuring the opening and closing of files, as well as the main loop, this approach should get you started.
$endgroup$
$begingroup$
I'm not sure I understand the reasoning behindfirst_line=next(lines)
could you explain how it should be used?
$endgroup$
– Emily Alden
Apr 1 at 18:22
$begingroup$
@EmilyAlden Why accept an answer when you don’t understand why that answer works?
$endgroup$
– David White
Apr 1 at 19:11
$begingroup$
@DavidWhite: Honestly I bounced between which answer to accept. I understand the use ofiter
andenumerate
here which are the main parts of the answer. The line I do not understand applies only once and I believe I can write around that line and get the results I want. (Still working on it though).
$endgroup$
– Emily Alden
Apr 1 at 19:36
1
$begingroup$
@EmilyAldenfirst_line = next(iterator)
is equivalent tofor first_line in iterator: break
$endgroup$
– wizzwizz4
Apr 1 at 19:48
$begingroup$
@wizzwizz4 Thank you.
$endgroup$
– Emily Alden
Apr 1 at 19:50
add a comment |
Your Answer
StackExchange.ifUsing("editor", function ()
return StackExchange.using("mathjaxEditing", function ()
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix)
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["\$", "\$"]]);
);
);
, "mathjax-editing");
StackExchange.ifUsing("editor", function ()
StackExchange.using("externalEditor", function ()
StackExchange.using("snippets", function ()
StackExchange.snippets.init();
);
);
, "code-snippets");
StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "196"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);
else
createEditor();
);
function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);
);
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcodereview.stackexchange.com%2fquestions%2f216653%2fread-write-a-pipe-delimited-file-line-by-line-with-some-simple-text-manipulation%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
A nice trick you can use in python is to open two (or more) files at once in one line. This is done with something like:
with open('file_one.txt', 'r') as file_one, open('file_two.txt', 'r') as file_two:
for line in file_one:
...
for line in file_two:
...
This is a very common way of reading from one file and writing to another without continually opening and closing one of them.
Currently, you're opening and closing the files with each iteration of the loop. Your program loops through the lines in name.txt
, checks an if
/ elif
condition, then if either are satisfied, a file is opened, written to, then closed again with every iteration of the loop.
Simply by opening both files at the same time you can stop opening and closing them repeatedly.
For more info on the with
statement and other context managers, see here.
Another small improvement can be made. At the moment, you check the first if
condition every time, but you know it will only actually evaluate to True
once. it would be better to remove that check and just always perform that block once. Assign counter after the first block (after where if counter == 1
currently is) then replace the elif
statement with a while
loop.
It would be worth getting familiar with PEP8 if you're going to use Python a lot in the future. It's a standard style guide and will help with the readability of your code (for you and others). Just small stuff like new lines after colons or spaces either side of variable declarations / comparisons.
If you include an example file and desired output, there may be more I can help with.
$endgroup$
$begingroup$
I decided to accept this answer as it has the information most pertinent to my skill level and it worked. (I couldn't get the iterative answer to produce the expected results). Thank you very much. I am modifying my code so that it will be PEP8 compliant.
$endgroup$
– Emily Alden
Apr 1 at 21:07
add a comment |
$begingroup$
A nice trick you can use in python is to open two (or more) files at once in one line. This is done with something like:
with open('file_one.txt', 'r') as file_one, open('file_two.txt', 'r') as file_two:
for line in file_one:
...
for line in file_two:
...
This is a very common way of reading from one file and writing to another without continually opening and closing one of them.
Currently, you're opening and closing the files with each iteration of the loop. Your program loops through the lines in name.txt
, checks an if
/ elif
condition, then if either are satisfied, a file is opened, written to, then closed again with every iteration of the loop.
Simply by opening both files at the same time you can stop opening and closing them repeatedly.
For more info on the with
statement and other context managers, see here.
Another small improvement can be made. At the moment, you check the first if
condition every time, but you know it will only actually evaluate to True
once. it would be better to remove that check and just always perform that block once. Assign counter after the first block (after where if counter == 1
currently is) then replace the elif
statement with a while
loop.
It would be worth getting familiar with PEP8 if you're going to use Python a lot in the future. It's a standard style guide and will help with the readability of your code (for you and others). Just small stuff like new lines after colons or spaces either side of variable declarations / comparisons.
If you include an example file and desired output, there may be more I can help with.
$endgroup$
$begingroup$
I decided to accept this answer as it has the information most pertinent to my skill level and it worked. (I couldn't get the iterative answer to produce the expected results). Thank you very much. I am modifying my code so that it will be PEP8 compliant.
$endgroup$
– Emily Alden
Apr 1 at 21:07
add a comment |
$begingroup$
A nice trick you can use in python is to open two (or more) files at once in one line. This is done with something like:
with open('file_one.txt', 'r') as file_one, open('file_two.txt', 'r') as file_two:
for line in file_one:
...
for line in file_two:
...
This is a very common way of reading from one file and writing to another without continually opening and closing one of them.
Currently, you're opening and closing the files with each iteration of the loop. Your program loops through the lines in name.txt
, checks an if
/ elif
condition, then if either are satisfied, a file is opened, written to, then closed again with every iteration of the loop.
Simply by opening both files at the same time you can stop opening and closing them repeatedly.
For more info on the with
statement and other context managers, see here.
Another small improvement can be made. At the moment, you check the first if
condition every time, but you know it will only actually evaluate to True
once. it would be better to remove that check and just always perform that block once. Assign counter after the first block (after where if counter == 1
currently is) then replace the elif
statement with a while
loop.
It would be worth getting familiar with PEP8 if you're going to use Python a lot in the future. It's a standard style guide and will help with the readability of your code (for you and others). Just small stuff like new lines after colons or spaces either side of variable declarations / comparisons.
If you include an example file and desired output, there may be more I can help with.
$endgroup$
A nice trick you can use in python is to open two (or more) files at once in one line. This is done with something like:
with open('file_one.txt', 'r') as file_one, open('file_two.txt', 'r') as file_two:
for line in file_one:
...
for line in file_two:
...
This is a very common way of reading from one file and writing to another without continually opening and closing one of them.
Currently, you're opening and closing the files with each iteration of the loop. Your program loops through the lines in name.txt
, checks an if
/ elif
condition, then if either are satisfied, a file is opened, written to, then closed again with every iteration of the loop.
Simply by opening both files at the same time you can stop opening and closing them repeatedly.
For more info on the with
statement and other context managers, see here.
Another small improvement can be made. At the moment, you check the first if
condition every time, but you know it will only actually evaluate to True
once. it would be better to remove that check and just always perform that block once. Assign counter after the first block (after where if counter == 1
currently is) then replace the elif
statement with a while
loop.
It would be worth getting familiar with PEP8 if you're going to use Python a lot in the future. It's a standard style guide and will help with the readability of your code (for you and others). Just small stuff like new lines after colons or spaces either side of variable declarations / comparisons.
If you include an example file and desired output, there may be more I can help with.
answered Apr 1 at 15:20
HoboProberHoboProber
4116
4116
$begingroup$
I decided to accept this answer as it has the information most pertinent to my skill level and it worked. (I couldn't get the iterative answer to produce the expected results). Thank you very much. I am modifying my code so that it will be PEP8 compliant.
$endgroup$
– Emily Alden
Apr 1 at 21:07
add a comment |
$begingroup$
I decided to accept this answer as it has the information most pertinent to my skill level and it worked. (I couldn't get the iterative answer to produce the expected results). Thank you very much. I am modifying my code so that it will be PEP8 compliant.
$endgroup$
– Emily Alden
Apr 1 at 21:07
$begingroup$
I decided to accept this answer as it has the information most pertinent to my skill level and it worked. (I couldn't get the iterative answer to produce the expected results). Thank you very much. I am modifying my code so that it will be PEP8 compliant.
$endgroup$
– Emily Alden
Apr 1 at 21:07
$begingroup$
I decided to accept this answer as it has the information most pertinent to my skill level and it worked. (I couldn't get the iterative answer to produce the expected results). Thank you very much. I am modifying my code so that it will be PEP8 compliant.
$endgroup$
– Emily Alden
Apr 1 at 21:07
add a comment |
$begingroup$
Here is another way to organize your code. Instead of an if
within the loop, use iterators more explicitly. Concretely:
with open(r"C:Pathname.txt") as source:
lines = iter(source)
# first line
first_line = next(lines)
with open(r"C:PATH2019.txt") as summary:
# ... omitted ...
# remaining lines
with open(r"C:PATHPythonWrittenData.txt", 'a') as dest:
for counter, line in enumerate(lines, start=1):
# ... omitted ...
I have also used enumerate
to update counter
and line
simultaneously.
The other answer has some more tips on writing good python code. But as far as structuring the opening and closing of files, as well as the main loop, this approach should get you started.
$endgroup$
$begingroup$
I'm not sure I understand the reasoning behindfirst_line=next(lines)
could you explain how it should be used?
$endgroup$
– Emily Alden
Apr 1 at 18:22
$begingroup$
@EmilyAlden Why accept an answer when you don’t understand why that answer works?
$endgroup$
– David White
Apr 1 at 19:11
$begingroup$
@DavidWhite: Honestly I bounced between which answer to accept. I understand the use ofiter
andenumerate
here which are the main parts of the answer. The line I do not understand applies only once and I believe I can write around that line and get the results I want. (Still working on it though).
$endgroup$
– Emily Alden
Apr 1 at 19:36
1
$begingroup$
@EmilyAldenfirst_line = next(iterator)
is equivalent tofor first_line in iterator: break
$endgroup$
– wizzwizz4
Apr 1 at 19:48
$begingroup$
@wizzwizz4 Thank you.
$endgroup$
– Emily Alden
Apr 1 at 19:50
add a comment |
$begingroup$
Here is another way to organize your code. Instead of an if
within the loop, use iterators more explicitly. Concretely:
with open(r"C:Pathname.txt") as source:
lines = iter(source)
# first line
first_line = next(lines)
with open(r"C:PATH2019.txt") as summary:
# ... omitted ...
# remaining lines
with open(r"C:PATHPythonWrittenData.txt", 'a') as dest:
for counter, line in enumerate(lines, start=1):
# ... omitted ...
I have also used enumerate
to update counter
and line
simultaneously.
The other answer has some more tips on writing good python code. But as far as structuring the opening and closing of files, as well as the main loop, this approach should get you started.
$endgroup$
$begingroup$
I'm not sure I understand the reasoning behindfirst_line=next(lines)
could you explain how it should be used?
$endgroup$
– Emily Alden
Apr 1 at 18:22
$begingroup$
@EmilyAlden Why accept an answer when you don’t understand why that answer works?
$endgroup$
– David White
Apr 1 at 19:11
$begingroup$
@DavidWhite: Honestly I bounced between which answer to accept. I understand the use ofiter
andenumerate
here which are the main parts of the answer. The line I do not understand applies only once and I believe I can write around that line and get the results I want. (Still working on it though).
$endgroup$
– Emily Alden
Apr 1 at 19:36
1
$begingroup$
@EmilyAldenfirst_line = next(iterator)
is equivalent tofor first_line in iterator: break
$endgroup$
– wizzwizz4
Apr 1 at 19:48
$begingroup$
@wizzwizz4 Thank you.
$endgroup$
– Emily Alden
Apr 1 at 19:50
add a comment |
$begingroup$
Here is another way to organize your code. Instead of an if
within the loop, use iterators more explicitly. Concretely:
with open(r"C:Pathname.txt") as source:
lines = iter(source)
# first line
first_line = next(lines)
with open(r"C:PATH2019.txt") as summary:
# ... omitted ...
# remaining lines
with open(r"C:PATHPythonWrittenData.txt", 'a') as dest:
for counter, line in enumerate(lines, start=1):
# ... omitted ...
I have also used enumerate
to update counter
and line
simultaneously.
The other answer has some more tips on writing good python code. But as far as structuring the opening and closing of files, as well as the main loop, this approach should get you started.
$endgroup$
Here is another way to organize your code. Instead of an if
within the loop, use iterators more explicitly. Concretely:
with open(r"C:Pathname.txt") as source:
lines = iter(source)
# first line
first_line = next(lines)
with open(r"C:PATH2019.txt") as summary:
# ... omitted ...
# remaining lines
with open(r"C:PATHPythonWrittenData.txt", 'a') as dest:
for counter, line in enumerate(lines, start=1):
# ... omitted ...
I have also used enumerate
to update counter
and line
simultaneously.
The other answer has some more tips on writing good python code. But as far as structuring the opening and closing of files, as well as the main loop, this approach should get you started.
answered Apr 1 at 15:39
Benjamin KuykendallBenjamin Kuykendall
75329
75329
$begingroup$
I'm not sure I understand the reasoning behindfirst_line=next(lines)
could you explain how it should be used?
$endgroup$
– Emily Alden
Apr 1 at 18:22
$begingroup$
@EmilyAlden Why accept an answer when you don’t understand why that answer works?
$endgroup$
– David White
Apr 1 at 19:11
$begingroup$
@DavidWhite: Honestly I bounced between which answer to accept. I understand the use ofiter
andenumerate
here which are the main parts of the answer. The line I do not understand applies only once and I believe I can write around that line and get the results I want. (Still working on it though).
$endgroup$
– Emily Alden
Apr 1 at 19:36
1
$begingroup$
@EmilyAldenfirst_line = next(iterator)
is equivalent tofor first_line in iterator: break
$endgroup$
– wizzwizz4
Apr 1 at 19:48
$begingroup$
@wizzwizz4 Thank you.
$endgroup$
– Emily Alden
Apr 1 at 19:50
add a comment |
$begingroup$
I'm not sure I understand the reasoning behindfirst_line=next(lines)
could you explain how it should be used?
$endgroup$
– Emily Alden
Apr 1 at 18:22
$begingroup$
@EmilyAlden Why accept an answer when you don’t understand why that answer works?
$endgroup$
– David White
Apr 1 at 19:11
$begingroup$
@DavidWhite: Honestly I bounced between which answer to accept. I understand the use ofiter
andenumerate
here which are the main parts of the answer. The line I do not understand applies only once and I believe I can write around that line and get the results I want. (Still working on it though).
$endgroup$
– Emily Alden
Apr 1 at 19:36
1
$begingroup$
@EmilyAldenfirst_line = next(iterator)
is equivalent tofor first_line in iterator: break
$endgroup$
– wizzwizz4
Apr 1 at 19:48
$begingroup$
@wizzwizz4 Thank you.
$endgroup$
– Emily Alden
Apr 1 at 19:50
$begingroup$
I'm not sure I understand the reasoning behind
first_line=next(lines)
could you explain how it should be used?$endgroup$
– Emily Alden
Apr 1 at 18:22
$begingroup$
I'm not sure I understand the reasoning behind
first_line=next(lines)
could you explain how it should be used?$endgroup$
– Emily Alden
Apr 1 at 18:22
$begingroup$
@EmilyAlden Why accept an answer when you don’t understand why that answer works?
$endgroup$
– David White
Apr 1 at 19:11
$begingroup$
@EmilyAlden Why accept an answer when you don’t understand why that answer works?
$endgroup$
– David White
Apr 1 at 19:11
$begingroup$
@DavidWhite: Honestly I bounced between which answer to accept. I understand the use of
iter
and enumerate
here which are the main parts of the answer. The line I do not understand applies only once and I believe I can write around that line and get the results I want. (Still working on it though).$endgroup$
– Emily Alden
Apr 1 at 19:36
$begingroup$
@DavidWhite: Honestly I bounced between which answer to accept. I understand the use of
iter
and enumerate
here which are the main parts of the answer. The line I do not understand applies only once and I believe I can write around that line and get the results I want. (Still working on it though).$endgroup$
– Emily Alden
Apr 1 at 19:36
1
1
$begingroup$
@EmilyAlden
first_line = next(iterator)
is equivalent to for first_line in iterator: break
$endgroup$
– wizzwizz4
Apr 1 at 19:48
$begingroup$
@EmilyAlden
first_line = next(iterator)
is equivalent to for first_line in iterator: break
$endgroup$
– wizzwizz4
Apr 1 at 19:48
$begingroup$
@wizzwizz4 Thank you.
$endgroup$
– Emily Alden
Apr 1 at 19:50
$begingroup$
@wizzwizz4 Thank you.
$endgroup$
– Emily Alden
Apr 1 at 19:50
add a comment |
Thanks for contributing an answer to Code Review Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcodereview.stackexchange.com%2fquestions%2f216653%2fread-write-a-pipe-delimited-file-line-by-line-with-some-simple-text-manipulation%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
$begingroup$
Can you edit your question to explain what the loop is supposed to do?
$endgroup$
– David White
Apr 1 at 14:28
$begingroup$
@DavidWhite Added. For quick reference: It reads one text file line by line, performs string manipulation, and then writes it into a new file line by line.
$endgroup$
– Emily Alden
Apr 1 at 14:56