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Questions tagged [file-writing]

This tag refers to the process of writing text or data to a file.

932 questions
425
votes
16 answers

How do I specify new lines in a string in order to write multiple lines to a file?

How can I indicate a newline in a string in Python, so that I can write multiple lines to a text file?
FabianCook
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290
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15 answers

How to redirect 'print' output to a file?

I want to redirect the print to a .txt file using Python. I have a for loop, which will print the output for each of my .bam file while I want to redirect all output to one file. So I tried to put: f = open('output.txt','w') sys.stdout = f at the…
LookIntoEast
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147
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11 answers

Writing a dictionary to a text file?

I have a dictionary and am trying to write it to a file. exDict = {1:1, 2:2, 3:3} with open('file.txt', 'r') as file: file.write(exDict) I then have the error file.write(exDict) TypeError: must be str, not dict So I fixed that error but…
Nic
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70
votes
8 answers

How do I write to a file in Kotlin?

I can't seem to find this question yet, but what is the simplest, most-idiomatic way of opening/creating a file, writing to it, and then closing it? Looking at the kotlin.io reference and the Java documentation I managed to get this: fun write() { …
yiwei
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39
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3 answers

Python writelines() and write() huge time difference

I was working on a script which reading a folder of files(each of size ranging from 20 MB to 100 MB), modifies some data in each line, and writes back to a copy of the file. with open(inputPath, 'r+') as myRead: my_list = myRead.readlines() …
Arjun Balgovind
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29
votes
4 answers

How to write the resulting RDD to a csv file in Spark python

I have a resulting RDD labelsAndPredictions = testData.map(lambda lp: lp.label).zip(predictions). This has output in this format: [(0.0, 0.08482142857142858), (0.0, 0.11442786069651742),.....] What I want is to create a CSV file with one column for…
Jason Donnald
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27
votes
2 answers

How to remove \n and \r from a string

I currently am trying to get the code from this website: http://netherkingdom.netai.net/pycake.html Then I have a python script parse out all code in html div tags, and finally write the text from between the div tags to a file. The problem is it…
HittmanA
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21
votes
1 answer

Atomic writing to file on linux

Is there a way to dump a buffer to file atomically? By "atomically" I mean: if for example someone terminates my application during writing, I'd like to have file in either before- or after-writing state, but not in a corrupted intermediate…
mambo_sun
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19
votes
7 answers

Write to a file with sudo privileges in Python

The following code throws an error if it's run by a non-root user for a file owned by root, even when the non-root user has sudo privileges: try: f = open(filename, "w+") except IOError: sys.stderr.write('Error: Failed to open file %s' %…
user2824889
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17
votes
3 answers

How to create a CSV file if it does not exist and then only append to it Python

I want to know how to create a file if it does not exist in the directory. I want to only append data. I am getting this error in Python: No such file or directory. This is my code: with open (saveAddr+".csv",'a') as allpckts: …
alphiii
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16
votes
6 answers

How to convert a PDF from base64 string to a file?

I have a PDF as a base64 string and I need to write it to file using Python. I tried this: import base64 base64String = "data:application/pdf;base64,JVBERi0xLjQKJeHp69MKMSAwIG9iago8PC9Qcm9kdWNlciAoU2tpYS9..." with open('temp.pdf', 'wb') as…
Rafael Miller
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16
votes
2 answers

Writing data to file in Dockerfile

I have a shell script, script.sh, that writes some lines to a file: #!/usr/bin/env bash printf "blah blah blah blah\n" | sudo tee file.txt Now in my Dockerfile, I add this script and run it, then attempt to add the generated file.txt: ADD…
pcsram
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13
votes
1 answer

How to bulk write TFRecords?

I have a CSV with approximately 40 million rows. Each row is a training instance. As per the documentation on consuming TFRecords I am trying to encode and save the data in a TFRecord file. All the examples I have found (even the ones in the…
Insectatorious
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13
votes
3 answers

Get text and rewrite(update) file contents in Python

I'm trying my hand at this rosalind problem and am running into an issue. I believe everything in my code is correct but it obviously isn't as it's not running as intended. i want to delete the contents of the file and then write some text to that…
Tare Gaskin
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11
votes
1 answer

Writing tab separated values in Go

I'm trying to write tab separated values in a file using the tabwriter package in Go. records map[string] []string file, err := os.OpenFile(some_file, os.O_CREATE|os.O_WRONLY, 0644) if err != nil { log.Println(err) } w :=…
user3502035
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