search and replace first amount of strings instances with one thing and a second amou

[chickflick91]

i have a code in python to search and replace what i need though is to replace the first say 10 instances of the number 1 with 2 and the second 10 instances with the number 3. anybody knows how to do that?


fin = open(r'F:\1\xxx.txt')
fout = open(r'F:\1\xxx2.txt', "wt")
for line in fin:
fout.write( line.replace('1', '2') )
fin.close()
fout.close()

[dwblas]

Use a counter to count the number of replaces

num_replaced=0
fin = open(r'F:\1\xxx.txt')
fout = open(r'F:\1\xxx2.txt', "wt")
replace_out="2"
ctr=0
for line in fin:
    fout.write( line.replace('1', replace_out) )
    ctr += 1
    if ctr > 9:
        replace_out="3"
        ctr=0
fin.close()
fout.close() 

[chickflick91]

didnt work for some reason. i tested putting in xxx.txt
1111111111
1111111111
and i got
2222222222
2222222222

in xxx2.txt

[chickflick91]

so i was given the code

with open(r'F:\1\xxx.txt') as fin:
lines = fin.read()
# get a list of all instances of number 1
all_index = [i for i,x in enumerate(lines) if i != 0 and lines[i-1:i+1] == 'x1']
# convert the file string into a list
list_lines = list(lines)
# replace the first 10 instances with 2;
# then the second 10 instances with 3
for i in all_index[:10]:
list_lines[i] = '2'
for i in all_index[10:20]:
list_lines[i] = '3'
# write the resulting string into output file
with open(r'F:\1\xxx2.txt','w') as fout:
fout.write(''.join(list_lines))




and it works in replacing the string 'x1'. which almost gets me exactly what i need but doesn't work with longer strings like 'stop1'. does anybody know why?

[dwblas]

I have no idea what you want to do, and "didn't work" provides no additional information.

didnt work for some reason. i tested putting in xxx.txt
1111111111
1111111111
and i got
2222222222
2222222222

when you said

replace the first say 10 instances of the number 1 with 2

Isn't that what it just did on each of these lines???

[chickflick91]

solved by code

get_all_index = lambda s : [i for i,_ in enumerate(lines) if i-len(s)+1 >= 0 and lines[i-len(s)+1:i+1] == s]


with open(r'F:\1\xxx.txt') as fin:
lines = fin.read()
# get a list of all instances of number 1
all_index = get_all_index('yyyy1')
# convert the file string into a list
list_lines = list(lines)
# replace the first 10 instances with 2;
# then the second 10 instances with 3
for i in all_index[:10]:
list_lines[i] = '2'
for i in all_index[10:20]:
list_lines[i] = '3'
# write the resulting string into output file
with open(r'F:\1\xxx2.txt','w') as fout:
fout.write(''.join(list_lines))