Question

elif search.lower() == "m":
    DMY = input("please enter your date of birth you are looking for (date/month/year) : ")
    DMY = DMY.split("/")
    DMY = DMY[1]

    for line in open("datafile.txt"):
        if DMY in line:
            print(line)

Answer 1

您可以使用异常处理：

DMY = input("please enter your date of birth you are looking for (date/month/year) :` ")
DMY = DMY.split("/", 2)
try:
    DMY = int(DMY[1])
except (IndexError, ValueError):
    # User did not use (enough) slashes or the middle value was not an integer
    print("Oops, did you put in an actual date?")

或者您可以尝试解析日期：

import datetime

DMY = input("please enter your date of birth you are looking for (date/month/year) :` ")
try:
    DMY = datetime.datetime.strptime(DMY, '%d/%m/%Y').date()
except ValueError:
    # User entered something that doesn't fit the pattern dd/mm/yyyy
    print("Oops, did you put in an actual date?")

后者的优势在于您现在拥有一个实际的datetime.date()对象，这不仅仅是检查用户是否输入了斜杠和整数;它还验证输入的值实际上可以解释为日期。 30/02/4321不会解析，因为即使在4321年，也没有2月30日。

Answer 2

使用find：

s = "29/01/2014"
if s.find("/") == -1:
    print "No '/' here!"
else:
    print "Found '/' in the string."

如何确保用户使用/？

2 个答案: