Python 3.x python文件读取问题FileNotFoundError

我正在学习一些python flie阅读并遇到一些问题

当我在桌面或其他地方打开txt文件时，它不在项目文件夹中 它不识字

file_path ='D:\summer2017\4\pi2.txt'
with open('pi2.txt')as file_object:
    content1=file_object.read()
    print(content1.rstrip())
#it works and print 3.14****
#D:\summer2017 is this project folder


file_path =r'F:\test\123.txt'
with open('123.txt')as file_object:
    content1=file_object.read()
    print(content1.rstrip())
#FileNotFoundError: [Errno 2] No such file or directory: '123.txt'
# i create a 123.txt in F:\test
# but it can not read

file_path =r'F:\test\pi2.txt'
with open('pi2.txt')as file_object:
    content1=file_object.read()
    print(content1.rstrip())
# i create another pi2.txt in F:\test
# now it can be found
# in this txt there are some random alphabet and nums but not 3.14****
# but it also print the pi num

您需要在open中指定路径，否则它将检查脚本的本地目录

with open(file_path) as file_object:

with open(file_path) as file_object: