Write down the tip for the practice: The Time in Words.
A dict was created for the time in number format to string format:
intToStrDict = {
1: 'one',
2: 'two',
3: 'three',
4: 'four',
5: 'five',
6: 'six',
7: 'seven',
8: 'eight',
9: 'nine',
10: 'ten',
11: 'eleven',
12: 'twelve',
13: 'thirteen',
14: 'fourteen',
15: 'quarter',
16: 'sixteen',
17: 'seventeen',
18: 'eighteen',
19: 'nineteen',
20: 'twenty',
30: 'half',
40: 'fourty',
50: 'fifty'
}
get() is a good way get the value of a key from the dict, so I tried following function to convert minute in number format to string format:
def minTowords(tempm):
return intToStrDict.get(tempm, ' '.join([intToStrDict.get( tempm // 10 * 10), intToStrDict.get( tempm % 10 )])
)
Unfortunately, it runs into the following error when the minute number is less than 10:
minTowords(3)
Traceback (most recent call last):
File "/Users/kz/Documents/C/Pys/test.py", line 538, in <module>
print(timeInWords(3, 1))
File "/Users/kz/Documents/C/Pys/test.py", line 533, in timeInWords
return "%s%s past %s" % (minTowords(m),'' if m in (15, 30) else ' minute' if m ==1 else ' minutes', intToStrDict[h])
File "/Users/kz/Documents/C/Pys/test.py", line 522, in minTowords
return intToStrDict.get(tempm, intToStrDict.get( tempm // 10 )+ ' '+intToStrDict.get( tempm % 10 ))
TypeError: unsupported operand type(s) for +: 'NoneType' and 'str'
It’s wired because 3 is defined in the dict already which means the default part : ’ ‘.join([intToStrDict.get( tempm // 10 * 10), intToStrDict.get( tempm % 10 )]) should not be executed.
For testing purpose, I modified the function to:
def minTowords(tempm):
return intToStrDict.get(tempm, ' '.join([intToStrDict.get( tempm // 10 * 10), ''])
)
with the same error:
minTowords(3)
Traceback (most recent call last):
File "/Users/kz/Documents/C/Pys/test.py", line 540, in <module>
minTowords(3)
File "/Users/kz/Documents/C/Pys/test.py", line 522, in minTowords
return intToStrDict.get(tempm, ' '.join([intToStrDict.get( tempm // 10 * 10), ''])
TypeError: sequence item 0: expected str instance, NoneType found
To check if the list operation causes the issue, tried with
def minTowords(tempm):
return intToStrDict.get(tempm, [intToStrDict.get( tempm // 10 * 10)])
it works. The root cause should be string operation: join()
Did another two testings for verification:
Join string with operator: ‘+’
def minTowords(tempm): return intToStrDict.get(tempm, intToStrDict.get( tempm // 10 * 10) + ' ' + intToStrDict.get( tempm % 10 ))Doesn’t work
Remove Join operation
def minTowords(tempm): return intToStrDict.get(tempm, [intToStrDict.get( tempm // 10 * 10), intToStrDict.get( tempm % 10 )])works
Finally, I made it by following code:
def minTowords(tempm):
if tempm in intToStrDict:
return intToStrDict[tempm]
return ' '.join([intToStrDict.get( tempm // 10 * 10), intToStrDict.get( tempm % 10 )])
Summary:
Be careful when a function was taken as default parameter of the get() method.
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