How to write new rows in a CSV using Python

Question

I have this code which generates a random number. I want it to save the random number on a new line/row every time it is run(the code).

I tried adding newLine and newRow but it did not work.

import csv
import random

newFile = open("random.csv",'w',newline='')
newWriter = csv.writer(newFile, dialect='excel')
newRow = []
case_number = random.randint(0,1000000000)
print("Your problem has been stored. We have allocated a case number which  will be sent off to a technician. Please take a note of your case number: ",  str(case_number))
newRow.append(case_number)
newWriter.writerow(newRow)
newFile.close()

And how can I shorten this piece of code?

Any help will be appreciated.

Thank you!

"it did not work". Why? What happened?

user5547025
– user5547025

2016-05-09 12:05:51 +00:00
Commented May 9, 2016 at 12:05 — user5547025
– user5547025, Commented May 9, 2016 at 12:05
Open the the file in append mode 'a' instead of 'w'.

JRodDynamite
– JRodDynamite

2016-05-09 12:06:53 +00:00
Commented May 9, 2016 at 12:06 — JRodDynamite
– JRodDynamite, Commented May 9, 2016 at 12:06

Yaron · Accepted Answer · 2016-05-09 13:03:49Z

1

I made some minor modification to the original code.

replaced "w" with "a" (append) as suggested by @ JRodDynamite - in order to save the previous data in the file, and append the new data

Added "with" - as suggested by @Display Name - which ensure that a resource is "cleaned up" when the code that uses it finishes running.

Defined the case_number to be string (cast of the random int).

I continued using CSV writer as used by @Jason Cole.

I removed the newRow and the append.

import csv
import random

with open("random.csv",'a') as newFile:
    newWriter = csv.writer(newFile, dialect='excel')
    case_number = str(random.randint(0,1000000000))
    print("Your problem has been stored. We have allocated a case number which  will be sent off to a technician. Please take a note of your case number: ",  case_number)
    newWriter.writerow([case_number])
    newFile.close()

edited May 9, 2016 at 13:03

answered May 9, 2016 at 12:12

Yaron

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2 Comments

Yaron Over a year ago

@Display Name - Thanks for the comment! added "with"

Maximilian Peters Over a year ago

Some explanation would be helpful as well, otherwise this will become reality: theallium.com/engineering/…

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