Python I/O 基本操作

8/20/2019 pythonleetcode

# New-Coder Input

牛客网上面刷题时可能用到的多组输入输出:

  • 输入 m, n 两个数:
str_in = input()
m, n = [int(_) for _ in str_in.split()]
  • 多组输入,第一行 n 表示数的数量,第二行输入这 n 个数:
n, m = input(), list(map(int, input().split()))
  • 输入有多组数据:
import sys

s = sys.stdin.readline().strip()
if not s:
    break

# Format Output

When output, we can use str() , repr() and print() , the different between them could be found in Python3 Tutorial (opens new window).

The usage of format , one thing to note :

print('{0} and {1}'.format('Google', 'Baidu'))
>>> Google and Baidu
print('{1} and {0}'.format('Google', 'Baidu'))
>>> Baidu and Google

print(f'some string')
# raw string

print('{0:2d} {1:3f}'.format(1,2))
# specifies the length of the placeholder

print('{name}: age}'.format(name = 'weigao', age = '18'))
>>> weigao: 18

The % also can be use to format output, but it is an old way, so use it as little as possible.

# Input

Python provides the input() function from the standard input to a line, and the default standard input is the keyboard.

str = input("please input: ")
print("your input is: ", str)

In Newcoder programming test, somethings we need custom input, there are some ways for us to reference:

  • Mutil input and output

例如第一行表示接下来要输入的行数,接下来若干行输入,并且涉及多组输入输出时:

while True:
    try:
        n = int(input())
        lists = [int(input()) for _ in range(n)]
        # the code
    except:
        break
更新时间: 2020年5月14日星期四 11:20