Question

The following code Ruby code will iterate the source string and produce a list of the cumulative words delimited by a ‘.’ character, other than those after the last ‘.’.

For example, give a source string of ‘Company.Dept.Group.Team’ the result will be …
[“Company.Dept.Group”, “Company.Dept”, “Company”]

Given that a while loop in Python (I believe) will test only an expression and not a statement as shown below, how would one best write this in idiomatic Python?

#ruby
source = 'Company.Dept.Group.Team'
results = []

temp = source.clone
while (i = temp.rindex('.'))  # test statement not supported in Python?
  temp = temp[0...i]
  results << temp
end

p results   # >> ["Company.Dept.Group", "Company.Dept", "Company"]

Answer 1

The Python idiom is something like this:

while True:
    i = temp.rindex('.')
    if not i:
        break
    ...