Python：提取文本文件中两个字符串之间的值

Question

I have a dialogue text file like this:

    Mom: 
Hi
    Dad: 
Hi
    Mom: 
Bye
    Dad: 
Bye
    Dad: 
:)

I have to copy both speakers lines to their own text files (mom.txt and dad.txt) This works but the problem is if there is two or more lines of same speaker in a row.

 def sort(path):
    inFile= open(path, 'r')
    inFile1= open(path, 'r')
    copy = False
    outFile = open('mom.txt', 'w')
    outFile1 = open('dad.txt', 'w')
    keepCurrentSet = False
    for line in inFile:
        if line.startswith("Dad:"):
            keepCurrentSet = False

        if keepCurrentSet:
            outFile.write(line)

        if line.startswith("Mom:"):
            keepCurrentSet = True

    for line1 in inFile1:
        if line1.startswith("Mom:"):
            keepCurrentSet = False

        if keepCurrentSet:
            outFile1.write(line1)

        if line1.startswith("Dad:"):
            keepCurrentSet = True


    outFile.close()        
    outFile1.close()
    inFile1.close()

The outFile1 outcome looks like this:

Hi
Bye
Dad:
:)

And should look like:

Hi
Bye
:)

Ideas or easier ways to do this? thanks

Answer 1

Here is one way you can write mom.txt and dad.txt in one single loop:

 def sort(path):
    inFile= open(path, 'r')
    inFile1= open(path, 'r')
    copy = False
    outFile = open('mom.txt', 'w')
    outFile1 = open('dad.txt', 'w')
    keepCurrentSetDad = False
    keepCurrentSetMom = False
    for line in inFile:
        print("--->",line)
        if 'Dad' in line:
            keepCurrentSetDad = True
            keepCurrentSetMom = False
            continue
        elif 'Mom' in line:
            keepCurrentSetMom = True
            keepCurrentSetDad = False
            continue
        if keepCurrentSetDad:
            outFile1.write(line)
        elif keepCurrentSetMom:
            outFile.write(line)
    outFile.close()        
    outFile1.close()
    inFile1.close()

I have merely edited your code. Please check your txt file. In whatever you have shown here, the speaker is on one line, and the speaker' words are in the next line. I have stuck to that format.

Answer 2

You can use:

def sort(path):
    with open(path) as f,\
            open('mom.txt', 'w') as mom,\
            open('dad.txt', 'w') as dad:
        curr = None # keep tracks of current speaker
        for line in f:
            if 'Mom:' in line:
                curr = 'Mom' # set the current speaker to Mom
            elif 'Dad:' in line:
                curr = 'Dad' # set the current speaker to Dad
            else:
                if curr == 'Mom':
                    mom.write(line)
                elif curr == 'Dad':
                    dad.write(line)

The resulting mom.txt and dad.txt file should look like:

# mom.txt
Hi
Bye

# dad.txt
Hi
Bye
:)

Answer 3

I've got even shorter answer where only one condition has to be checked inside the loop. Depending on your language version, you can choose one of the two:

Python 3.7+

def sort(path):
    with open(path, 'r') as inFile, open('mom.txt', 'w+') as momFile, open('dad.txt', 'w+') as dadFile:
        line = inFile.readline()
        while line != '':
            if line.startswith('Mom:'):
                momFile.write(inFile.readline())
            elif line.startswith('Dad:'):
                dadFile.write(inFile.readline())
            line = inFile.readline()

Python 3.8+, (notice the walrus operator := )

def sort(path):
    with open(path, 'r') as inFile, open('mom.txt', 'w+') as momFile, open('dad.txt', 'w+') as dadFile:
        while (line := inFile.readline()) != '':
            if line.startswith('Mom:'):
                momFile.write(inFile.readline())
            elif line.startswith('Dad:'):
                dadFile.write(inFile.readline())

Output:

mom.txt:
Hi
Bye

dad.txt:
Hi
Bye
:)

Let me know if you spot some mistake or a possible improvement.