temp.readline()为空？

Question

我能够创建和写入临时文件,但是当读取文件行时为空.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(或倒回)临时文件才能从中读取:

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,调用时文件指针位于文件末尾temp.readline().