Solution 1

``````def positions(a_string, first_word, second_word, third_word):
result = ''
if first_word in a_string:
result += str(a_string.index(first_word))
else:
result += '-'
result += ','

if second_word in a_string:
result += str(a_string.index(second_word))
else:
result += '-'
result += ','

if third_word in a_string:
result += str(a_string.index(third_word))
else:
result += '-'

return result
``````

# Positions

Write a function `positions` that receives a string and 3 words, and gives you the positions of those words in the original string. Example:

``````# Positions:
#         0                         26      34
phrase = "Python is good. Python is Wise. I like Python"
positions(phrase, 'Python', 'Wise', 'like')  # "0,26,34"
``````

If the word doesn't exist in the original string, it should backfill using dashes. Example:

``````# Positions:
#         0                         26
phrase = "Python is good. Python is Wise. I like Python"
positions(phrase, 'Python', 'Wise', 'Ruby')  # "0,26,-" (Ruby doesn't exist)
``````

### Test Cases

test one occurrence third word -

``````def test_one_occurrence_third_word():
# Positions:
#         0                         26      34
phrase = "Python is good. Python is Wise. I like Python"
assert positions(phrase, 'Javscript', 'Ruby', 'Wise') == "-,-,26"
``````

test two occurrences missing first -

``````def test_two_occurrences_missing_first():
# Positions:
#         0                         26      34
phrase = "Python is good. Python is Wise. I like Python"
assert positions(phrase, 'Ruby', 'Wise', 'like') == "-,26,34"
``````

test two occurrences missing third -

``````def test_two_occurrences_missing_third():
# Positions:
#         0                         26      34
phrase = "Python is good. Python is Wise. I like Python"
assert positions(phrase, 'Python', 'Wise', 'Ruby') == "0,26,-"
``````

test one occurrence first word -

``````def test_one_occurrence_first_word():
# Positions:
#         0                         26      34
phrase = "Python is good. Python is Wise. I like Python"
assert positions(phrase, 'Python', 'Javascript', 'Ruby') == "0,-,-"
``````

test three occurrences -

``````def test_three_occurrences():
# Positions:
#         0                         26      34
phrase = "Python is good. Python is Wise. I like Python"
assert positions(phrase, 'Python', 'Wise', 'like') == "0,26,34"
``````

test one occurrence second word -

``````def test_one_occurrence_second_word():
# Positions:
#         0                         26      34
phrase = "Python is good. Python is Wise. I like Python"
assert positions(phrase, 'Javscript', 'like', 'Ruby') == "-,34,-"
``````
def positions(a_string, first_word, second_word, third_word): pass