How should i replace a word in a specific line in a file (python)

Question

I have one file called tenantdetails(tdetails.txt) I want to replace one of the data inside but the other similar data I dont want them to be affected. This is my file:

T001,ly,0500505,male,17,johor,butterworth ,adam,long,
T002,ll,06060606,female,19,johor,kl,lili ,short,
T003,xh,030303,male,17,juru,hotel,adik,...,

So, this is my code:

def word_search(key, filename):
    with open(filename,"r") as file:  # opening the file using with to ensure it closes after the block of code is executed
        lines = file.readlines()  # reading the lines of the files in order
    for number, line in enumerate(lines, 1):  # using enumerate to map each line of the file to it's line_number
        if key in line:  # searching for the keyword in file
            return( number)  # returning the line number if the keyword

def replace_line(file,old,new):
    key=input("Enter keyword")
    line_num=word_search(key,file)
    print(line_num)

    filedata=''
    with open(file,"r") as f:
        for line in f:
            if old in line[line_num]:
                line= line.replace(old, new)
            filedata += line
    with open(file,"w") as f:
         f.write(filedata)

How should i change the Johor for T001, but T002 will not affected

Answer 1

Loop through every line and when the correct line is found loop through every word until the correct word is found.

I would recommend that instead of trying to edit the line in the file you completely rewrite the file with the edited line.