python - 在 for 循环中运行 replace() 方法？

Question

太晚了，我一直在尝试编写一个简单的脚本来将点云数据重命名为工作格式。我不知道我做错了什么，因为底部的代码工作正常。为什么 for 循环中的代码不起作用？它正在将它添加到列表中，但它只是没有被替换功能格式化。抱歉，我知道这不是调试器，但我真的坚持这个，其他人可能需要 2 秒才能看到问题。

# Opening and Loading the text file then sticking its lines into a list []
filename = "/Users/sacredgeometry/Desktop/data.txt"
text = open(filename, 'r')
lines = text.readlines()
linesNew = []
temp = None


# This bloody for loop is the problem
for i in lines:
    temp = str(i)
    temp.replace(' ', ', ',2)
    linesNew.append(temp)


# DEBUGGING THE CODE    
print(linesNew[0])
print(linesNew[1])

# Another test to check that the replace works ... It does!
test2 = linesNew[0].replace(' ', ', ',2)
test2 = test2.replace('\t', ', ')
print('Proof of Concept: ' + '\n' + test2)


text.close()

Answer 1

您没有将 replace() 的返回值分配给任何东西。此外，readlines 和 str(i) 是不必要的。

试试这个:

filename = "/Users/sacredgeometry/Desktop/data.txt"
text = open(filename, 'r')
linesNew = []

for line in text:
    # i is already a string, no need to str it
    # temp = str(i)

    # also, just append the result of the replace to linesNew:
    linesNew.append(line.replace(' ', ', ', 2))

# DEBUGGING THE CODE    
print(linesNew[0])
print(linesNew[1])

# Another test to check that the replace works ... It does!
test2 = linesNew[0].replace(' ', ', ',2)
test2 = test2.replace('\t', ', ')
print('Proof of Concept: ' + '\n' + test2)  

text.close()