python - temp.readline() 为空？

Question

我能够创建和写入临时文件，但是在读取文件时行是空的。我确认临时文件有内容。这是我的代码。谢谢

import tempfile
temp = tempfile.NamedTemporaryFile()

with open("~/somefile.txt") as inf:
    for line in inf:
        if line==line.lstrip():
            temp.write(line)

line = str(temp.readline()).strip()
print line #nothing

Answer 1

您必须重新打开（或倒带）临时文件，然后才能从中读取：

import tempfile
temp = tempfile.NamedTemporaryFile()

with open("~/somefile.txt") as inf:
    for line in inf:
        if line==line.lstrip():
            temp.write(line)

temp.seek(0) # <=============== ADDED

line = str(temp.readline()).strip()
print line

否则，当您调用temp.readline().