为什么格式化会导致print（）失败？

Question

我创建了一个名为P1Puts[]]的二维数组。在格式化输出之前，我想用它做的一切都很好。有人能告诉我为什么格式化输出会导致错误“tuple index out of range”？我使用实时数据从shell创建了下面的示例。请注意，“第1次尝试，共2次”工作正常，但“第2次尝试，共2次”会产生一个错误。你知道吗

#=================================================
# TRIAL 1 OF 2:

>>> 
>>> for r in range(9):
    print('r',r,P1Puts[r][2])


r 0 51.73
r 1 51.8
r 2 60.46
r 3 34.62
r 4 49.69
r 5 87.93
r 6 33.37
r 7 42.59
r 8 54.6
>>> 
#=================================================
# TRIAL 2 OF 2: 
# (Note that all I did below was add formatting
#  to the third argument in print()

>>> for r in range(9):
    print('r',r,"{6.2f}".format(P1Puts[r][2]))


Traceback (most recent call last):
  File "<pyshell#21>", line 2, in <module>
    print('r',r,"{6.2f}".format(P1Puts[r][2]))
IndexError: tuple index out of range
>>> 

Answer 1

您缺少一个:

for r in range(9):
    print('r',r,"{:6.2f}".format(P1Puts[r][2])) # : ← missing