在python中打印混合列表

Question

I am using Python 3.6. I am using Learn Python the hard way as reference.

I have a mixed list and I am trying to print the elements. The books says to use

format code "r" since we don't know what's in the list. But I am getting error with this.

Was this working in previous versions? How can I print mixed list, each element a time.

Here is my code and error:

change = [1,'pennies',2,'dimes',3,'quarters']
for i in change:
print("I got {:r}".format(i))

Error Stack trace:

Traceback (most recent call last):
  File "<pyshell#52>", line 2, in <module>
    print("I got {:r}".format(i))
ValueError: Unknown format code 'r' for object of type 'int'

Thanks

Answer 1

For str.format , the "force to repr " conversion is done with !r . not :r ; it's not asserting a type for conversion, it's saying "don't use __format__ at all, use __repr__ to perform the conversion". Make it:

print("I got {!r}".format(i))