在这个特殊的例子中，它是csv并不重要，因为您只是希望对文本文件执行搜索和替换。
正如@Tim Roberts所评论的，这可以使用命令行工具（sed -e s/jpg/jpeg/ < sample.csv）来完成，但无论如何，让我们用Python来完成它......
试试这个可运行的例子！

#!/usr/bin/env python
# to set up let's recreate the file
with open("sample.csv",'w') as f:
    f.write("""
Alfa,Beta,Charlie,Delta,Echo
A1,B1,C1,D1,AX1.jpg
A2,B2,C2,D2,BX1.jpg
A3,B3,C3,D3,CX1.jpg
A4,B4,C4,D4,BX1.jpg
A4,B4,C4,D4,CX1.jpg
A4,B4,C4,D4,AX1.jpg
""")

# now read the file into a string
with open('sample.csv') as csv_file:
    full_text = csv_file.read()
    
# correct the string
new_full_text = full_text.replace(".jpg", ".jpeg")

# overwrite the original file
with open('sample.csv', 'w') as csv_file:
    csv_file.write(new_full_text)
    
# check the output

desired_output = """
Alfa,Beta,Charlie,Delta,Echo
A1,B1,C1,D1,AX1.jpeg
A2,B2,C2,D2,BX1.jpeg
A3,B3,C3,D3,CX1.jpeg
A4,B4,C4,D4,BX1.jpeg
A4,B4,C4,D4,CX1.jpeg
A4,B4,C4,D4,AX1.jpeg
"""
with open('sample.csv') as csv_file:
    check_full_text = csv_file.read()

print(check_full_text == desired_output)

check_full_text

<script src="https://modularizer.github.io/pyprez/pyprez.min.js"></script>