问题
I'd like to type in my input from command lines after running
if __name__ == "__main__":
data = list(map(int, sys.stdin.readline().split()))
print(data)
n, capacity = data[0:2]
values = data[2:(2 * n + 2):2]
weights = data[3:(2 * n + 2):2]
A sample input could be:
2 40
20 2
30 3
My questions are:
1) How to create the list data using my input?
2) How can I let Python know I have finished the input and it should execute the rest of the code?
回答1:
The solution to this problem depends on the OS you're using.
Basically, if you want multiline input, you'll have to use sys.stdin.read() instead of sys.stdin.readline(). Since sys.stdin is a file-like object in Python, the read() method will read until it reaches the end of a file. It is marked by a special character EOF (end-of-file). On different OS'es there is a different way of sending it.
On Windows:
Press Ctrl+Z after your input and then press Enter:
2 10
20 2
30 3
^Z
On a Unix-based OS:
Press Ctrl+D after your input. No Enter is required (I believe)
If you want to get a list [2, 10, 20, 2, 30, 3] from your input, you're fine. The split() method splits by whitespace (spaces, newlines, etc.).
回答2:
I agree with everything @Leva7 has said. Nonetheless, I'd suggest another solution, which is to use raw_input for Python 2 or input for Python 3 like so:
args = []
s = raw_input() # input() for Python 3
while s != '':
args.extend([int(arg) for arg in s.strip().split()])
s = raw_input()
Of course, that's not a one-liner in any way, but it does the job and it's easy to see how it's done. Plus, no special characters are required at the end of the input.
回答3:
If you are on Windows make sure you finish your input with newline, otherwise ^Z (from pressing Ctrl-Z) will be included in your input. Also make sure you use English language layout - https://stackoverflow.com/a/17924627/9205085
来源：https://stackoverflow.com/questions/36798798/using-sys-stdin-readline-to-read-multiple-lines-from-cmd-in-python