Python 使用列表在每个月内添加适当的天数

当代码执行if this == that or that1 or that2:时，它会像预期的那样对this和that进行比较，但是它不会对其余变量进行相同的比较.相反，它和if that1:一样，只是一张真实的支票.

例如:

>>> a = 1
>>> b = 2
>>> c = 3
>>> if a == b or c:
...     print("This code runs even though a does not equal b or c")
...
This code runs even though a does not equal b or c
>>> if a == b or a == c:
...     print("this will not print because a does not equal b or c")
...
>>> 

比较它们的正确方法如下所示:

if month == Jan or month == Mar or month == May or month == Jul or month == Aug or month == Oct or month == Dec:
    month.append(listOfSteps[:31])
    del listOfSteps[:31]
    print('31 days')

• 更好的解决方案可能是这样的:

if month in [Jan, Mar, May, ...]:
    month.append(...)
    ...

回应您的 comments :当您在python中比较list时，它会对它们进行元素级的比较，如果您希望将两个不同的list与相同的内容进行比较，这是一个问题.

例如:

>>> a = [1]
>>> b = [1]
>>> c = a
>>> if c == b:
...    print("The contents are the same so this will print")
The contents are the same so this will print

这个问题的解决方案是使用id()函数执行身份比较，而不是直接相互比较.

比如:

if id(month) in [id(i) for i in [Jan, Mar, Apr ...]]:
    month.append(...)
    ...

因此，考虑到所有这些，try 以下方法:

#Initilize lists
listOfSteps = []
Jan = []
Feb = []
Mar = []
Apr = []
May = []
Jun = []
Jul = []
Aug = []
Sept = []
Oct = []
Nov = []
Dec = []

# Open file into program and insert data into list called listOfSteps
step_file = open('/Users/gregoryyelverton/Desktop/Data files/steps.txt', 'r')

for line in step_file:
        line = line.rstrip('\n')
        listOfSteps.append(line)

# Create list with all months inside
months = [Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sept, Oct, Nov, Dec]

# Iterate through list containing months and insert the days within those months

for month in months:
    #print(month)
    if id(month) in [id(i) for i in [Jan,Mar,May,Jul,Aug,Oct,Dec]]:
        month.append(listOfSteps[:31])
        del listOfSteps[:31]
        print('31 days')

    elif id(month) in [id(i) for i in [Apr,Jun,Sept,Nov]]:
        month.append(listOfSteps[:30])
        del listOfSteps[:30]
        print('30 days')

    else:    
        month.append(listOfSteps[:28])
        del listOfSteps[:28]
        print('28 days')