$ 502: ip
Python 3.6.4 |Anaconda, Inc.| (default, Jan 16 2018, 12:04:33)
Type 'copyright', 'credits' or 'license' for more information
IPython 6.2.1 -- An enhanced Interactive Python. Type '?' for help.
In [1]: # Comments by Richard Careaga (Nostromo) on niemasd guarantee 2018-03-04
...: def print_info(a):
...: n = len(a)
...: avg = 0.0
...: for i in range(n):
...: print("Element #%d is %d" % (i,a[i]))
...: avg += a[i]
...: avg /= n
...: print("Average is %f" % avg)
...:
In [2]: print_info(15)
...:
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-2-088e45cb4e72> in <module>()
----> 1 print_info(15)
<ipython-input-1-02fda1e35bcf> in print_info(a)
1 # Comments by Richard Careaga (Nostromo) on niemasd guarantee 2018-03-04
2 def print_info(a):
----> 3 n = len(a)
4 avg = 0.0
5 for i in range(n):
TypeError: object of type 'int' has no len()
In [3]: arg = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15]
...:
In [4]: print_info(arg)
...:
Element #0 is 1
Element #1 is 2
Element #2 is 3
Element #3 is 4
Element #4 is 5
Element #5 is 6
Element #6 is 7
Element #7 is 8
Element #8 is 9
Element #9 is 10
Element #10 is 11
Element #11 is 12
Element #12 is 13
Element #13 is 14
Element #14 is 15
Average is 8.000000
In [5]: # Too bad about lists being zero indexed
...:
...: # Without parsing the C++ code, it is not obvious that the argument to
...: # print_info is a list, rather than an int, so some error trapping is
...: # needed
...: import operator
...: def print_info2(a):
...: if isinstance(a, list):
...: n = len(a)
...: avg = 0.0
...: for i in range(n):
...: print("Element #%d is %d" % (i,a[i]))
...: avg += a[i]
...: avg /= n
...: return print("Average is %f" % avg)
...: else:
...: return print("Error: The argument to this function, 'a' must be a list.")
...:
In [6]: print_info2(15)
...:
Error: The argument to this function, 'a' must be a list.
In [7]: print_info2(arg)
...:
Element #0 is 1
Element #1 is 2
Element #2 is 3
Element #3 is 4
Element #4 is 5
Element #5 is 6
Element #6 is 7
Element #7 is 8
Element #8 is 9
Element #9 is 10
Element #10 is 11
Element #11 is 12
Element #12 is 13
Element #13 is 14
Element #14 is 15
Average is 8.000000
In [8]: # However, transliterating from C++ is entirely unPythonic, anyway
...: import operator
...: def print_info3(a):
...: if isinstance(a, list):
...: for element in a:
...: print("Element #%d is %d" % (element, element))
...: print("Average is %f" % (sum(a)/len(a)))
...: else:
...: return print("Error: The argument to this function, 'a' must be a list")
...:
In [9]: print_info3(15)
...:
Error: The argument to this function, 'a' must be a list
In [10]: print_info3(arg)
...:
Element #1 is 1
Element #2 is 2
Element #3 is 3
Element #4 is 4
Element #5 is 5
Element #6 is 6
Element #7 is 7
Element #8 is 8
Element #9 is 9
Element #10 is 10
Element #11 is 11
Element #12 is 12
Element #13 is 13
Element #14 is 14
Element #15 is 15
Average is 8.000000
In [11]: