如何在Python中連接一個固定的字符串和一個變量

Question

我想在主題中包含文件名'main.txt'，以便通過命令行傳遞文件名。但這樣做

python sample.py main.txt #running python with argument 

msg['Subject'] = "Auto Hella Restart Report "sys.argv[1] #line where i am using that passed argument 

Answer 1

我猜你的意思是這樣做收到錯誤：

msg['Subject'] = "Auto Hella Restart Report " + sys.argv[1] 
# To concatenate strings in python, use  ^

Answer 2

試試看

msg['Subject'] = "Auto Hella Restart Report " + sys.argv[1] 

+運算符在Python來連接字符串覆蓋。

Answer 3

如果您需要添加兩個字符串，你必須使用「+」操作符

因此

msg['Subject'] = your string + sys.argv[1] 

，你也必須在開始時導入SYS

爲

import sys 

msg['Subject'] = "Auto Hella Restart Report " + sys.argv[1] 

Answer 4

variable=" Hello..." 
print (variable) 
print("This is the Test File "+variable) 

整數類型...

variable=" 10" 
print (variable) 
print("This is the Test File "+str(variable))