Develop Reference

IndexError: list index out of range - PythonError

I'm creating a program that should create a file (.txt) based on each line of 'clouds.txt'. This is my code:
def CreateFile():
global file_name
f = open(file_name,"w+")
f.write(list_email + ":")
f.close()
def WriteInConfig():
f = open("config/config.txt","a")
f.write(list_name + "\n")
f.close()
with open("clouds.txt","r") as f:
list_lines = sum(1 for line in open('clouds.txt'))
lines = f.readline()
for line in lines:
first_line = f.readline().strip()
list_email = first_line.split('|')[1] #email
print("Email: " + list_email)
list_pass = first_line.split('|')[2] #pass
print("Pass: " + list_pass)
list_name = first_line.split('|')[3] #name
print(list_name)
global file_name
file_name = "config/." + list_name + ".txt"
with open('clouds.txt', 'r') as fin:
data = fin.read().splitlines(True)
with open('clouds.txt', 'w') as fout:
fout.writelines(data[1:])
CreateFile()
WriteInConfig()
The clouds.txt file looks like this:
>|clouds.n1c0+mega01#gmail.com|cwSHklDIybllCD1OD4M|Mega01|15|39.91|FdUkLiW0ThDeDkSlqRThMQ| |x
|clouds.n1c0+mega02#gmail.com|tNFVlux4ALC|Mega02|50|49.05|lq1cTyp13Bh9-hc6cZp1RQ|xxx|x
|clouds.n1c0+mega03#gmail.com|7fe4196A4CUT3V|Mega03|50|49.94|BzW7NOGmfhQ01cy9dAdlmg|xxx|xxx >
Everything works fine until 'Mega48'. There I get "IndexError: list index out of range"
>|clouds.n1c0+mega47#gmail.com|bd61t9zxcuC1Yx|Mega47|50|10|Xjff6C8mzEqpa3VcaalUuA|xxx|x
|clouds.n1c0+mega48#gmail.com|kBdnyB6i0PUyUb|Mega48|50|0|R6YfuGP2hvE-uds0ylbQtQ|xxx|x
|clouds.n1c0+mega49#gmail.com|OcAdgpS4tmSLTO|Mega49|50|28.65|xxx| >
I checked and there are no spaces/other characters. As you could see, after creating the file, the program deletes the line. After the error, if I'm starting the program again (and starts from 'Mega47') it doesn't show the error, and everything works as planned.
Any ideas how to fix this?

I see many mistakes in your code. First, what do you want with this list_lines = sum(1 for line in open('clouds.txt'))?
You have a problem in your for loop because you did lines = f.readline() so lines is the first line, then you do for line in lines where line will be each character of the first line and there are more character in the first line than lines in your file to read.
[edited]
you don't need to know the number of lines in the file to do a for loop. You can just do for line in f:, then you don't need to read the line again with readline it is already in the variable line

change and miss columns from text file in python

I have a text file with below data and trying to change columns and write into another file.
Here the input is
a|b|c|d|e|f
d|f|g|h|y|s
Like that i have 1000 rows
Now i want to swap the columns and also don't want all the columns and then write into another file.
The output i need is - I don't need 2 columns from the input
c|d|a|b
g|h|d|f
I tried like below and it's not working
with open("old.txt","r") as file,open('new.txt', 'w') as outfile:
freader = csv.reader(file, delimiter = '|')
for line in file:
line[3], line[4],line[1],line[2]
outfile.write(line)
Any help is more appreciated.

import csv
with open('old.csv', 'r') as f_in, open('new.csv', 'w') as f_out:
freader = csv.reader(f_in, delimiter = '|')
fwriter = csv.writer(f_out, delimiter = '|')
for line in freader:
fwriter.writerow([line[2], line[3], line[0], line[1]])
File old.csv:
a|b|c|d|e|f
d|f|g|h|y|s
File new.csv:
c|d|a|b
g|h|d|f

for line in file: while this is valid syntax, you should use the cvsreader that you created. Replace this with for line in freader:
line[3], line[4],line[1],line[2] This line does nothing, you should store it in a variable. Replace this with newline = line[2] + "|" + line[3] + "|" + line[0] + "|" + line[1]. This builds a string with | in between each character.
outfile.write(line) You are writing the same line that you read. Replace this with outfile.write(newline + "\n"). This will write the string we created to the file. Adding \n will add a newline at the end of each line
with open("old.txt","r") as file,open('new.txt', 'w') as outfile:
freader = csv.reader(file, delimiter = '|')
for line in freader:
newline = line[2] + "|" + line[3] + "|" + line[0] + "|" + line[1]
outfile.write(newline + "\n")

Keeping the quotes when reading CSV file in python

Truoble with a really annoying homework. I have a csv-file with lots of comma-delimitered fields per row. I need to take the last two fields from every row and write them into a new txt-file. The problem is that some of the latter fields have sentences, those with commas are in double quotes, those without them aren't. For example:
180,easy
240min,"Quite easy, but number 3, wtf?"
300,much easier than the last assignment
I did this and it worked just fine, but the double quotes disappear. The assignment is to copy the fields to the txt-file, use semicolon as delimiter and remove possible line breaks. The text must remain exactly the same. We have an automatic check system, so it's no use arguing if this makes any sense.
import csv
file = open('myfile.csv', 'r')
output= open('mytxt.txt', 'w')
csvr = csv.reader(file)
headline = next(csvr)
for line in csvr:
lgt = len(line)
time = line[lgt - 2].replace('\n', '')
feedb = line[lgt - 1].replace('\n', '')
if time != '' and feedb != '':
output.write(time + ';' + feedb + '\n')
output.close()
file.close()
Is there some easy solution for this? Can I use csv module at all? No one seems to have exactly the same problem.
Thank you all beforehand.

Try this,
import csv
file = open('myfile.csv', 'r')
output= open('mytxt.txt', 'w')
csvr = csv.reader(file)
headline = next(csvr)
for line in csvr:
lgt = len(line)
time = line[lgt - 2].replace('\n', '')
feedb = line[lgt - 1].replace('\n', '')
if time != '' and feedb != '':
if ',' in feedb:
output.write(time + ';"' + feedb + '"\n')
else:
output.write(time + ';' + feedb + '\n')
output.close()
file.close()

Had to do it the ugly way, the file was too irrational. Talked with some collaegues on the same course and apparently the idea was NOT to use csv module here, but to rehearse basic file handling in Python.
file = open('myfile.csv','r')
output = open('mytxt.txt', 'w')
headline = file.readline()
feedb_lst = []
count = 0
for line in file:
if line.startswith('1'): #found out all lines should start with an ID number,
data_lst = line.split(',', 16) #that always starts with '1'
lgt = len(data_lst)
time = data_lst[lgt - 2]
feedb = data_lst[lgt - 1].rstrip()
feedback = [time, feedb]
feedb_lst.append(feedback)
count += 1
else:
feedb_lst[count - 1][1] = feedb_lst[count - 1][1] + line.rstrip()
i = 1
for item in feedb_lst:
if item[0] != '' and item[1] != '':
if i == len(feedb_lst):
output.write(item[0] + ';' + item[1])
else:
output.write(item[0] + ';' + item[1] + '\n')
i += 1
output.close()
file.close()
Thank you for your help!

Replace string in line without adding new line?

I want to replace string in a line which contain patternB, something like this:
from:
some lines
line contain patternA
some lines
line contain patternB
more lines
to:
some lines
line contain patternA
some lines
line contain patternB xx oo
more lines
I have code like this:
inputfile = open("d:\myfile.abc", "r")
outputfile = open("d:\myfile_renew.abc", "w")
obj = "yaya"
dummy = ""
item = []
for line in inputfile:
dummy += line
if line.find("patternA") != -1:
for line in inputfile:
dummy += line
if line.find("patternB") != -1:
item = line.split()
dummy += item[0] + " xx " + item[-1] + "\n"
break
outputfile.write(dummy)
It do not replace the line contain "patternB" as expected, but add an new line below it like :
some lines
line contain patternA
some lines
line contain patternB
line contain patternB xx oo
more lines
What can I do with my code?

Of course it is, since you append line to dummy in the beginning of the for loop and then the modified version again in the "if" statement. Also why check for Pattern A if you treat is as you treat everything else?
inputfile = open("d:\myfile.abc", "r")
outputfile = open("d:\myfile_renew.abc", "w")
obj = "yaya"
dummy = ""
item = []
for line in inputfile:
if line.find("patternB") != -1:
item = line.split()
dummy += item[0] + " xx " + item[-1] + "\n"
else:
dummy += line
outputfile.write(dummy)

The simplest will be:
1. Read all File into string
2. Call string.replace
3. Dump string to file

If you want to keep line by line iterator
(for a big file)
for line in inputfile:
if line.find("patternB") != -1:
dummy = line.replace('patternB', 'patternB xx oo')
outputfile.write(dummy)
else:
outputfile.write(line)
This is slower than other responses, but enables big file processing.

This should work
import os
def replace():
f1 = open("d:\myfile.abc","r")
f2 = open("d:\myfile_renew.abc","w")
ow = raw_input("Enter word you wish to replace:")
nw = raw_input("Enter new word:")
for line in f1:
templ = line.split()
for i in templ:
if i==ow:
f2.write(nw)
else:
f2.write(i)
f2.write('\n')
f1.close()
f2.close()
os.remove("d:\myfile.abc")
os.rename("d:\myfile_renew.abc","d:\myfile.abc")
replace()

You can use str.replace:
s = '''some lines
line contain patternA
some lines
line contain patternB
more lines'''
print(s.replace('patternB', 'patternB xx oo'))

how to read the content of .txt file using python?

output_filename = r"C:\Users\guage\Output.txt"
RRA:
GREQ-299684_6j
GREQ-299684_6k
CZM:
V-GREQ-299684_6k
V-GREQ-299524_9
F_65624_1
R-GREQ-299680_5
DUN:
FB_71125_1
FR:
VQ-299659_18
VR-GREQ-299659_19
VEQ-299659_28
VR-GREQ-299659_31
VR-GREQ-299659_32
VEQ-299576_1
GED:
VEQ-299622_2
VR-GREQ-299618_13
VR-GREQ-299559_1
VR-GREQ-299524_14
FB_65624_1
VR-GREQ-299645_1
MNT:
FB_71125_1
FB_71125_2
VR-534_4
The above is the content of the the .txt file. how can I read it separately the content of it. for example -
RRA:VR-GREQ-299684_6j VR-GREQ-299684_6k VR-GREQ-299606_3 VR-GREQ-299606_4 VR-GREQ-299606_5 VR-GREQ-299606_7
and save it in a variable or something similar to it. Later I want to read CZM separately and so on. I did as below.
with open(output_filename, 'r') as f:
excel = f.read()
But how to read it separately ? can someone tell me how to do it ?

Something like this:
def read_file_with_custom_record_separator(file_path, delimiter='\n'):
fh = open(file_path)
data = ""
for line in fh:
if line.strip().endswith(delimiter) and data != "":
print "VARIABLE:\n<", data, ">\n"
data = line
else:
data += line
print "LAST VARIABLE:\n<", data, ">\n"
And then:
read_file_with_custom_record_separator("input.txt", ":")

You can make use of the file text : as indicator to create a new file like this:
savefilename = ""
with open(filename, 'r') as f:
for line in f:
line = line.strip() # get rid of the unnecessary white chars
lastchar = line[-1:] # get the last char
if lastchar == ":": # if the last char is ":"
savefilename = line[0:-1] # get file name from line (except the ":")
sf = open(savefilename + ".txt", 'w') # create a new file
else:
sf.write(line + "\n") # write the data to the opened file
Then you should get collection of files:
RRA.txt
CZM.txt
DUN.txt
# etc
which contains all the appropriate data:
RRA.txt
VR-GREQ-299684_6j
VR-GREQ-299684_6k
VR-GREQ-299606_3
VR-GREQ-299606_4
VR-GREQ-299606_5
VR-GREQ-299606_7
CZM.txt
VR-GREQ-299684_6k
VR-GREQ-299606_6
VR-GREQ-299606_8
VR-GREQ-299640_1
VR-GREQ-299640_5
VR-GREQ-299524_9
FB_65624_1
VR-GREQ-299680_5
DUN.txt
FB_71125_1
# and so on
You can replace the sf = open and the sf.write which whatever way you feel best to separate the data. Here, I use files...

You can iterate over the file and use the lines and indices to your advantage; something like this:
with open(output_filename, 'r') as f:
for index, line in enumerate(f):
# here you have access to each line and its index
# so you can save any number of lines you wish

What about reading it into a list, then process its element as you prefer
>>> f = open('myfile.txt', 'r').readlines()
>>> len(f)
46
>>> f[0]
RRA:
>>> f[-1]
VR-GREQ-299534_4
>>> f[:3]
['RRA:\n', 'VR-GREQ-299684_6j \n', 'VR-GREQ-299684_6k \n']
>>>
>>> [l for l in f if l.startswith('FB_')]
['FB_65624_1 \n', 'FB_71125_1 \n', 'FB_69228_1 \n', 'FB_65624_1 \n', 'FB_71125_1 \n', 'FB_71125_2 \n']
>>>