Develop Reference

List Indexing - Read File, Find Specific String, Replace String, Output New File

I have the following code, which i am attempting to read any file in, line by line searching for specific values from a list. If a value from within the old list is found, replace the found string with the same index position from old list with that of the new list value. All while maintaining the original document format.
Old_IDs = ['V-635771', 'V-616641']
New_IDs = ['V-250319', 'V-220123']
path = input('Input File Location: ')
file_type = input('Output File Type: ')
fin = open(path, "rt")
fout = open("SomeFile." + file_type, "wt")
for line in fin
#read replace the string and write to output file
fout.write(line.replace('V-635771', 'V-250319')
fin.close()
fout.close()
While I have to code working for individual values, I am finding it difficult to properly reference the list and replace the string with the associated index properly.

You could either use a dictionary as a look-up table or have another for-loop checking the list of values.
I also recommend you use the with syntax when opening a file, then you don't need to manually close it in the end.
with open("foo", "w") as bar:
bar.write("Hello")
Using a for-loop in your example and assuming Old_IDs and New_IDs will be of the same length and any index in Old_IDs will correspond with the proper New_IDs index.
Old_IDs = ['V-635771', 'V-616641']
New_IDs = ['V-250319', 'V-220123']
path = input('Input File Location: ')
file_type = input('Output File Type: ')
with open(path, "rt") as file:
fin = file.readlines()
with open("SomeFile." + file_type, "wt") as fout:
for line in fin:
for i, ID in enumerate(Old_IDs):
if ID in line:
line.replace(ID, New_IDs[i])
fout.write(line)
With a dictionary as a look-up table.
ID_map = {'V-635771': 'V-250319', 'V-616641': 'V-220123'}
path = input('Input File Location: ')
file_type = input('Output File Type: ')
with open(path, "rt") as file:
fin = file.readlines()
with open("SomeFile." + file_type, "wt") as fout:
for line in fin:
for ID in ID_map:
if ID in line:
line.replace(ID, ID_map[ID])
fout.write(line)

If I understand the question correctly, you just need to use the zip function.
Old_IDs = ['V-635771', 'V-616641']
New_IDs = ['V-250319', 'V-220123']
path = input('Input File Location: ')
file_type = input('Output File Type: ')
fin = open(path, "rt")
fout = open("SomeFile." + file_type, "wt")
for line in fin
#read replace the string and write to output file
for old, new in zip(Old_IDs, New_IDs):
fout.write(line.replace(old, new))
fin.close()
fout.close()

Read a specific line from a file index

how can I read a specific line from a file?
user.txt:
root
admin
me
you
When I do
def load_user():
file = open("user.txt", "r")
nextuser_line = file.readline().strip()
print(nextuser_line)
file.close()
root will be printed, but I would like to read admin from the file. So I try to read the next line index using [1]
def load_user():
file = open("user.txt", "r")
nextuser_line = file.readline().strip()
print(nextuser_line[1])
file.close()
instead of printing 'admin', the output is 'o' from 'root', but not the next line from the file.
what am I doing wrong?

readline() reads the first line. To access lines through index, use readlines():
def load_user():
file = open("user.txt", "r")
lines = file.readlines()
print(lines[1])
file.close()
>>> load_user()
'admin'
To remove the \n from the lines, use:
lines = [x.strip() for x in file]

So I just created a text file and copied text from an already existing file using a with loop. How do I open newly created file in same prog?

I'm making a program that takes text from an input file, then you input a file where it copies the already existing file text. Then, I need to replace a few words there and print the count of how many of these words were replaced. This is my code so far, but since with loops close the newly created file, I have no idea how to open it back again for reading and writing and counting. This is my awful code so far:
filename=input("Sisesta tekstifaili nimi: ")
inputFile=open(filename, "r")
b=input("Sisesta uue tekstifaili nimi: ")
uusFail=open(b+".txt", "w+")
f=uusFail
with inputFile as input:
with uusFail as output:
for line in input:
output.write(line)
lines[]
asendus = {'hello':'tere', 'Hello':'Tere'}
with uusFail as infile
for line in infile
for src, target in asendus
line = line, replace(src, target)
lines.append(line)
with uusFail as outfile:
for line in lines:
outfile.write(line)

There are a lot of unnecessary loops in your code. when you read the file, you can treat it as a whole and count the number of occurrences and replace them. Here is a modified version of your code:
infile = input('Enter file name: ')
outfile = input('enter out file: ')
with open(infile) as f:
content = f.read()
asendus = {'hello':'tere', 'Hello':'Tere'}
my_count = 0
for src, target in asendus.items():
my_count += content.count(src)
content = content.replace(src, target)
with open(f'{outfile}.txt','w+' ) as f:
f.write(content)

You need to reopen the file in the second block of code:
with open(b+".txt", "r") as infile:

How to replace a string in a file?

I have 2 numbers in two similar files. There is a new.txt and original.txt. They both have the same string in them except for a number. The new.txt has a string that says boothNumber="3". The original.txt has a string that says boothNumber="1".
I want to be able to read the new.txt, pick the number 3 out of it and replace the number 1 in original.txt.
Any suggestions? Here is what I am trying.
import re # used to replace string
import sys # some of these are use for other code in my program
def readconfig():
with open("new.text") as f:
with open("original.txt", "w") as f1:
for line in f:
match = re.search(r'(?<=boothNumber=")\d+', line)
for line in f1:
pattern = re.search(r'(?<=boothNumber=")\d+', line)
if re.search(pattern, line):
sys.stdout.write(re.sub(pattern, match, line))
When I run this, my original.txt gets completely cleared of any text.
I did a traceback and I get this:
in readconfig
for line in f1:
io.UnsupportedOperationo: not readable
UPDATE
I tried:
def readconfig(original_txt_path="original.txt",
new_txt_path="new.txt"):
with open(new_txt_path) as f:
for line in f:
if not ('boothNumber=') in line:
continue
booth_number = int(line.replace('boothNumber=', ''))
# do we need check if there are more than one 'boothNumber=...' line?
break
with open(original_txt_path) as f1:
modified_lines = [line.startswith('boothNumber=') if not line
else 'boothNumber={}'.format(booth_number)
for line in f1]
with open(original_txt_path, mode='w') as f1:
f1.writelines(modified_lines)
And I get error:
booth_number = int(line.replace('boothNumber=', ''))
ValueError: invalid literal for int() with base 10: '
(workstationID="1" "1" window=1= area="" extra parts of the line here)\n
the "1" after workstationID="1" is where the boothNumber=" " would normally go. When I open up original.txt, I see that it actually did not change anything.
UPDATE 3
Here is my code in full. Note, the file names are changed but I'm still trying to do the same thing. This is another idea or revision I had that is still not working:
import os
import shutil
import fileinput
import re # used to replace string
import sys # prevents extra lines being inputed in config
# example: sys.stdout.write
def convertconfig(pattern):
source = "template.config"
with fileinput.FileInput(source, inplace=True, backup='.bak') as file:
for line in file:
match = r'(?<=boothNumber=")\d+'
sys.stdout.write(re.sub(match, pattern, line))
def readconfig():
source = "bingo.config"
pattern = r'(?<=boothNumber=")\d+' # !!!!!!!!!! This probably needs fixed
with fileinput.FileInput(source, inplace=True, backup='.bak') as file:
for line in file:
if re.search(pattern, line):
fileinput.close()
convertconfig(pattern)
def copyfrom(servername):
source = r'//' + servername + '/c$/remotedirectory'
dest = r"C:/myprogram"
file = "bingo.config"
try:
shutil.copyfile(os.path.join(source, file), os.path.join(dest, file))
except:
print ("Error")
readconfig()
# begin here
os.system('cls' if os.name == 'nt' else 'clear')
array = []
with open("serverlist.txt", "r") as f:
for servername in f:
copyfrom(servername.strip())
bingo.config is my new file
template.config is my original
It's replacing the number in template.config with the literal string "r'(?<=boothNumber=")\d+'"
So template.config ends up looking like
boothNumber="r'(?<=boothNumber=")\d+'"
instead of
boothNumber="2"

To find boothNumber value we can use next regular expression (checked with regex101)
(?<=\sboothNumber=\")(\d+)(?=\")
Something like this should work
import re
import sys # some of these are use for other code in my program
BOOTH_NUMBER_RE = re.compile('(?<=\sboothNumber=\")(\d+)(?=\")')
search_booth_number = BOOTH_NUMBER_RE.search
replace_booth_number = BOOTH_NUMBER_RE.sub
def readconfig(original_txt_path="original.txt",
new_txt_path="new.txt"):
with open(new_txt_path) as f:
for line in f:
search_res = search_booth_number(line)
if search_res is None:
continue
booth_number = int(search_res.group(0))
# do we need check if there are more than one 'boothNumber=...' line?
break
else:
# no 'boothNumber=...' line was found, so next lines will fail,
# maybe we should raise exception like
# raise Exception('no line starting with "boothNumber" was found')
# or assign some default value
# booth_number = -1
# or just return?
return
with open(original_txt_path) as f:
modified_lines = []
for line in f:
search_res = search_booth_number(line)
if search_res is not None:
line = replace_booth_number(str(booth_number), line)
modified_lines.append(line)
with open(original_txt_path, mode='w') as f:
f.writelines(modified_lines)
Test
# Preparation
with open('new.txt', mode='w') as f:
f.write('some\n')
f.write('<jack Fill workstationID="1" boothNumber="56565" window="17" Code="" area="" section="" location="" touchScreen="False" secureWorkstation="false">')
with open('original.txt', mode='w') as f:
f.write('other\n')
f.write('<jack Fill workstationID="1" boothNumber="23" window="17" Code="" area="" section="" location="" touchScreen="False" secureWorkstation="false">')
# Invocation
readconfig()
# Checking output
with open('original.txt') as f:
for line in f:
# stripping newline character
print(line.rstrip('\n'))
gives
other
<jack Fill workstationID="1" boothNumber="56565" window="17" Code="" area="" section="" location="" touchScreen="False" secureWorkstation="false">

Python search a file for text using input from another file

I'm new to python and programming. I need some help with a python script. There are two files each containing email addresses (more than 5000 lines). Input file contains email addresses that I want to search in the data file(also contains email addresses). Then I want to print the output to a file or display on the console. I search for scripts and was able to modify but I'm not getting the desired results. Can you please help me?
dfile1 (50K lines)
yyy#aaa.com
xxx#aaa.com
zzz#aaa.com
ifile1 (10K lines)
ccc#aaa.com
vvv#aaa.com
xxx#aaa.com
zzz#aaa.com
Output file
xxx#aaa.com
zzz#aaa.com
datafile = 'C:\\Python27\\scripts\\dfile1.txt'
inputfile = 'C:\\Python27\\scripts\\ifile1.txt'
with open(inputfile, 'r') as f:
names = f.readlines()
outputlist = []
with open(datafile, 'r') as fd:
for line in fd:
name = fd.readline()
if name[1:-1] in names:
outputlist.append(line)
else:
print "Nothing found"
print outputlist
New Code
with open(inputfile, 'r') as f:
names = f.readlines()
outputlist = []
with open(datafile, 'r') as f:
for line in f:
name = f.readlines()
if name in names:
outputlist.append(line)
else:
print "Nothing found"
print outputlist

Maybe I'm missing something, but why not use a pair of sets?
#!/usr/local/cpython-3.3/bin/python
data_filename = 'dfile1.txt'
input_filename = 'ifile1.txt'
with open(input_filename, 'r') as input_file:
input_addresses = set(email_address.rstrip() for email_address in input_file.readlines())
with open(data_filename, 'r') as data_file:
data_addresses = set(email_address.rstrip() for email_address in data_file.readlines())
print(input_addresses.intersection(data_addresses))

mitan8 gives the problem you have, but this is what I would do instead:
with open(inputfile, "r") as f:
names = set(i.strip() for i in f)
output = []
with open(datafile, "r") as f:
for name in f:
if name.strip() in names:
print name
This avoids reading the larger datafile into memory.
If you want to write to an output file, you could do this for the second with statement:
with open(datafile, "r") as i, open(outputfile, "w") as o:
for name in i:
if name.strip() in names:
o.write(name)

Here's what I would do:
names=[]
outputList=[]
with open(inputfile) as f:
for line in f:
names.append(line.rstrip("\n")
myEmails=set(names)
with open(outputfile) as fd, open("emails.txt", "w") as output:
for line in fd:
for name in names:
c=line.rstrip("\n")
if name in myEmails:
print name #for console
output.write(name) #for writing to file

I think your issue stems from the following:
name = fd.readline()
if name[1:-1] in names:
name[1:-1] slices each email address so that you skip the first and last characters. While it might be good in general to skip the last character (a newline '\n'), when you load the name database in the "dfile"
with open(inputfile, 'r') as f:
names = f.readlines()
you are including newlines. So, don't slice the names in the "ifile" at all, i.e.
if name in names:

I think you can remove name = fd.readline() since you've already got the line in the for loop. It'll read another line in addition to the for loop, which reads one line every time. Also, I think name[1:-1] should be name, since you don't want to strip the first and last character when searching. with automatically closes the files opened.
PS: How I'd do it:
with open("dfile1") as dfile, open("ifile") as ifile:
lines = "\n".join(set(dfile.read().splitlines()) & set(ifile.read().splitlines())
print(lines)
with open("ofile", "w") as ofile:
ofile.write(lines)
In the above solution, basically I'm taking the union (elements part of both sets) of the lines of both the files to find the common lines.