Python の検索と置換は、ファイル編集時の可変テキスト長をどのように処理できるのでしょうか?

# Get user input for search and replacement text
textToSearch, textToReplace, fileToSearch = input("Text to search for: "), input("Text to replace it with: "), input("File to perform Search-Replace on: ")

# Open the file and loop through each line
with open(fileToSearch, 'r+') as tempFile:
    for line in fileinput.input(fileToSearch):
        # Perform replacement only when a match is found
        if textToSearch in line:
            line = line.replace(textToSearch, textToReplace)
        # Write the modified line back to the file
        tempFile.write(line)

# Read the file into memory
with open('file.txt', 'r') as file:
    filedata = file.read()

# Perform the replacement
filedata = filedata.replace('abcd', 'ram')

# Write the modified content back to the file
with open('file.txt', 'w') as file:
    file.write(filedata)