Using Python 3 on a windows machine:
I have a function to take a list of lists and open it as a csv file using my default application (excel). Despite closing the file after writing, I get a 'locked for editing' message when excel starts.
def opencsv(data):
"""saves a list of lists as a csv and opens"""
import tempfile
import os
import csv
handle, fn = tempfile.mkstemp(suffix='.csv')
with open(fn,"w", encoding='utf8',errors='surrogateescape',\
newline='') as f:
writer=csv.writer(f)
for row in data:
try:
writer.writerow(row)
except Exception as e:
print ('Error in writing row:',e)
f.close()
url = 'file://' + fn.replace(os.path.sep, '/')
os.startfile(fn)
opencsv([['d1','d2'],['d3','d4','d5']])
How can I fix this?
Answer from swstephe's input:
The issue is that mkstemp opens the file and associates it with an os handle. In my original code I was not closing this file properly. See below for updated code.
def opencsv(data):
"""saves a list of lists as a csv and opens"""
import tempfile
import os
import csv
handle, fn = tempfile.mkstemp(suffix='.csv')
with os.fdopen(handle,"w", encoding='utf8',errors='surrogateescape',\
newline='') as f:
writer=csv.writer(f)
for row in data:
try:
writer.writerow(row)
except Exception as e:
print ('Error in writing row:',e)
print (fn)
os.startfile(fn)
Related
I am trying to write my output into a file what my code is doing is that its looking for matched file names and storing it into a file similary for unmatched files but the problem is when i use write it overwrites the file and when i use append on every run it keeps on appending the file matched file names. What i need is that it refresh te file whenever the script is run and loads it with current data only.
import re
import sys
import os
import glob
import pandas as pd
import logging
try:
for file in glob.glob('*.csv'):
r = re.search(r'abc_sales_(20[0-9][0-9])-([1-9]|1[0-2]|0[0-9])-([1-9]|1[0-9]|2[0-9]|3[0-1]|0[0-9])-[0-9]{2}_[a-z0-9]{3,5}.csv', file)
if r:
#matched=file
print(f'File matched:{file}')
fp=open('bad_lines.txt', 'r+')
sys.stdout = fp
else:
path=f'File not matched:{file}'
f=open('filenotmatched.txt','a')
f.seek(0)
f.truncate()
f.write(path+'\n')
f.close()
except Exception as e:
pass
Suggested changes to your code.
import re
import sys
import os
import glob
import pandas as pd
import logging
# We create new 'bad_lines.txt' and
# 'filenotmatched.txt' for each run
with open('bad_lines.txt', 'w') as f_badlines, open('filenotmatched.txt','w') as f_notmatched:
try:
for file in glob.glob('*.csv'):
r = re.search(r'abc_sales_(20[0-9][0-9])-([1-9]|1[0-2]|0[0-9])-([1-9]|1[0-9]|2[0-9]|3[0-1]|0[0-9])-[0-9]{2}_[a-z0-9]{3,5}.csv', file)
if r:
#matched=file
#print(f'File matched:{file}')
#fp=open('bad_lines.txt', 'r+')
# ** Not clear why you redirected
# ** standard out to a file
# ** rather than writing to file directly
#sys.stdout = fp
f_badlines.write(f'File matched:{file}\n')
else:
path=f'File not matched:{file}'
#f=open('filenotmatched.txt','a')
#f.seek(0)
#f.truncate()
#f.write(path+'\n')
#f.close()
f_notmatched.write(path + '\n')
except Exception as e:
pass
I want to output csv file with python. I have gone through below code and it is working well with .txt file but I am unable to print csv through it.
import os
import tempfile
filename = tempfile.mktemp(".txt")
open (filename , "w").write ("Printing file")
os.startfile(filename, "print")
Actually I want to print a csv file that had been already created, there will be no need to write and create new file then print it out.
Edit: From print I meant hardcopy print through printer
If you want to print the content of a csv you can try this:
import csv
file_path = 'a.csv'
with open(file_path) as file:
content = csv.reader(file)
for row in content:
print(row)
I was talking about printing csv file as hardcopy with python code.
def printing():
#reading from csv writing in txt
with open("CSV_files//newfile.txt", "w") as my_output_file:
cs = pd.read_csv("CSV_files\\attendance.csv",header=None,index_col=None)
with open("CSV_files//attendance.csv", "r") as my_input_file:
[ my_output_file.write(" | ".join(row)+'\n') for row in csv.reader(my_input_file)]
my_output_file.close()
#reading from file and storing into reader and converting into string as .write() takes string
strnew = ""
with open('CSV_files//newfile.txt',"r") as f:
reader = f.read()
strnew = reader
#for checking
with open('CSV_files//print.txt',"w") as f:
f.write(strnew)
#printing
filename = tempfile.mktemp("attendance.txt")#creating a temp file
open (filename , "w").write(strnew)
os.startfile(filename, "print")
messagebox.showinfo("Print","Printing Request sent successfully!")
For more info:
github project link
I'm currently making a program that requires a JSON database file. I want the program to check for the file, if it's there then it's perfect, run the rest of the program, but if it doesn't exist create 'Accounts.json' with {} inside the file, instead then run the program.
How would I do this? Whats the most efficient way.
Note: I use this for checking, but how would I create the file:
def startupCheck():
if os.path.isfile(PATH) and os.access(PATH, os.R_OK):
# checks if file exists
print ("File exists and is readable")
else:
print ("Either file is missing or is not readable")
I believe you could simply do:
import io
import json
import os
def startupCheck():
if os.path.isfile(PATH) and os.access(PATH, os.R_OK):
# checks if file exists
print ("File exists and is readable")
else:
print ("Either file is missing or is not readable, creating file...")
with io.open(os.path.join(PATH, 'Accounts.json'), 'w') as db_file:
db_file.write(json.dumps({}))
This is how i did it. I hope it helps.
edit, yeey it looks like a code now :D
import json
import os
def where_json(file_name):
return os.path.exists(file_name)
if where_json('data.json'):
pass
else:
data = {
'user': input('User input: '),
'pass': input('Pass input: ')
}
with open('data.json', 'w') as outfile:
json.dump(data, outfile)
How about wrapping the open file in a try/except? I'm not a professional Python coder, so feel free to weigh in if this is not a kosher approach.
try:
with open('Accounts.json', 'r') as fp:
accounts = json.load(fp)
except IOError:
print('File not found, will create a new one.')
accounts = {}
# do stuff with your data...
with open('Accounts.json', 'w') as fp:
json.dump(accounts, fp, indent=4)
w+ opens with write permissions.
The + creates a new file if one is not found.
filename = 'jsonDB.json'
def openFile():
with open(filename, 'w+') as f:
f.write('{}')
f.close
openFile()
here is my code, i added exception to indexerror, but its not writing to csv file.
import urllib2
import csv
import time
import requests
import os
#a = open(r"C:\Drive F data\Client\Blake\III\2.txt")
a = ['http://www.houzz.com/trk/aHR0cDovL3d3dy5SSUtCLmNvbQ/b020157b98711b4a190eee3331eb0066/ue/MjA5ODg2MQ/1b9b00b9fdc9f270f14688046ef161e2',
'http://www.houzz.com/trk/aHR0cDovL3d3dy5nc2NhYmluZXRyeS5jb20/0323b7db059b9e0357d045685be21a6d/ue/NDY2MjE0/d8815293352eb2a6e40c95060c019697',
'http://www.houzz.com/trk/aHR0cDovL3NpY29yYS5jb20/dc807b3705b95b5da772a7aefe23a803/ue/Njc0NDA4/a73f8bdb38e10abd5899fb5c55ff3548',
'http://www.houzz.com/trk/aHR0cDovL3d3dy5DYXNlRGVzaWduLmNvbQ/d79c6af934e3c815d602c4d79b0d6617/ue/OTY3MDg/ce9a87e31e84871a96bca7538aae9856',
'http://www.houzz.com/trk/aHR0cDovL2phcnJldHRkZXNpZ25sbGMuY29t/9d0009d3544d9c22f6058b20097321b3/ue/MzExNTk1NA/310d49732d317725364368ea3fbfd7c1',
'http://www.houzz.com/trk/aHR0cDovL3d3dy5yb2JlcnRsZWdlcmVkZXNpZ24uY29t/8ac7311be2f794654cefba71474563f7/ue/MTExNTQ4/af201ffdc62de6aba9e2de90f69a770d']
with open("C:\Drive F data\Blake\III/2.csv", "ab")as export:
names = ['source','link']
writer = csv.DictWriter(export, fieldnames=names)
writer.writeheader()
for each in a:
try:
link = urllib2.urlopen(each).geturl()
except IndexError:
pass
print each, link
writer.writerow({'source':each,'link':link})
After removing try & exception , it works fine
I think you miss escape character in your file path. "C:\\Drive F data\\Blake\\III\\2.csv"
I have written this code
import os
import csv
import time
class upload_CSV:
def __init__(self):
coup = []
self.coup = coup
self.csv_name = 'Coup.csv'
def loader(self,rw):
with open(self.csv_name,'rb') as csv_file:
reader = csv.reader(csv_file,delimiter=',')
for row in reader:
self.coup.append(row[rw])
self.coup = self.coup[1:]
csv_file.flush()
csv_file.close()
return self.coup
def update(self,rw,message):
#try:
with open(self.csv_name,'rb') as csv_file1:
reader = csv.reader(csv_file1,delimiter=',')
csv_file1.flush()#To clean the register for reuse
csv_file1.close()
#except Exception as ex:
#error = 'An error occured loading data in the reader'
# #raise
# return ex
os.remove(self.csv_name)
writer = csv.writer(open(self.csv_name,'wb'))
for row in reader:
if row[rw]==message:
print str(row),' has been removed'
else:
writer.writerow(row)
return message
I am trying to read the content of a csv to a list first. Once i get the relevant data, i need to go back to my csv and create a new entry without that record. I keep getting the single error
Line 27 in update
with open(csv_name,'rb')as csvfile1:
Python: IOError: [Errno 2] No such file or directory 'Coup.csv'
when i call the Update function
I have looked at this question Python: IOError: [Errno 2] No such file or directory but nothing seems to work. Its as if the first function has a lock on the file. Any help would be appreciated
It would be enormously helpful if we saw the traceback to know exactly what line is producing the error...but here is a start...
First, you have two spots in your code where you are working with a filename that expects to only be available in the current directory. That is one possible point of failure in your code if you run it outside the directory containing the file:
self.csv_name = 'Coup.csv'
...
with open(self.csv_name,'rb') as csv_file:
...
with open('Coup.csv~','rb') as csv_file1:
...
And then, you are also referring to a variable that won't exist:
def update(self,rw,message):
...
# self.csv_name? or csv_file1?
os.remove(csv_name)
writer = csv.writer(open(csv_name,'wb'))
Also, how can you be sure this temp file will exist? Is it guaranteed? I normally wouldn't recommend relying on a system-temporary file.
with open('Coup.csv~','rb') as csv_file1: