字符串格式与列表和元组的区别

Question

What is the difference in below statements:

exam_st_date = (11,12,2014)

print( "The examination will start from : %i / %i / %i"%exam_st_date)

When i execute this python statement i get output: The examination will start from: 11 / 12 / 2014

But if i change exam_st_date = (11,12,2014) to

exam_st_date = [11,12,2014] 

as a list format

and if i execute same statement again then i gets error

C:\Users\bambored>python C:\Python\examdate.py
Traceback (most recent call last):
  File "C:\Python\examdate.py", line 6, in <module>
    print('The examination will start from : %i / %i / %i'%exam_st_date)
TypeError: %i format: a number is required, not list

Answer 1

you are getting a TypeError. It means that the variable you are passing to your print function is not of the required type. You are asked to pass an integer and not a list. Python is treating the list you created as one single object and not as 3 integers.

In your working example, you are using a tuple, which is recognized as 3 integer variables.