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

[Bill]

Bill wrote:
> validationmail1 at gmail.com wrote:
>> 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?
> Do you mean the (integer) number 1 or the character '1'? For instance, 
> if the first line of the file is:
> "There were 100 cats in the yard."
> Do you want to change this to
> "There were 200 cats in the yard."?
> Remember that string objects are "immutable" so your code probably 
> wouldn't work exactly like that.

I now realize that my last line does not apply. I suggest you start by 
just thinking about changing the first ten ones to twos.  Once you do 
that, you should have little trouble finishing the job. Being a Python 
newbie myself, your example helped motivate me to try my own example.  I 
used "type" to learn the data type of line (in your example), about 
which I was curious. My first concern was that is might only be 
"interable" object, but I learned that more is true.

>
>
>>
>> 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()
>