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== 8.5#h(0.6em)Splitting/joining strings


  
    
=== Learning objectives


    By the end of this section you should be able to


    - Use the split() method to split a string into substrings.
- Combine objects in a list into a string using join() method.


  
  
    
=== split()


    A string in Python can be broken into substrings given a #strong[delimiter]. A delimiter is also referred to as a separator. The #strong[split()] method, when applied to a string, splits the string into substrings by using the given argument as a delimiter. Ex: "1-2".split('-') returns a list of substrings \["1", "2"\]. When no arguments are given to the split() method, blank space characters are used as delimiters. Ex: "1\\t2\\n3 4".split() returns \["1", "2", "3", "4"\].


    #notebox("Note", rgb("#8a94a6"), rgb("#556666"), rgb("#f7f8fa"))[
#emph[split() for breaking down the string into tokens]


      #link("https://www.openstax.org/r/split-function")[split() for breaking down the string into tokens; ch 8, video 7]
]


    #notebox("Note", rgb("#8a94a6"), rgb("#556666"), rgb("#f7f8fa"))[
#emph[Examples of string delimiters and split() method]
]


  
  
    
=== join()


    The #strong[join()] method is the inverse of the split() method: a list of string values are concatenated together to form one output string. When joining string elements in the list, the delimiter is added in-between elements. Ex: ','.join(\["this", "is", "great"\]) returns "this,is,great".


    #notebox("Note", rgb("#8a94a6"), rgb("#556666"), rgb("#f7f8fa"))[
#emph[join() for combining tokens into one string]


      #link("https://www.openstax.org/r/join-function")[join() for combing tokens into one string; ch 8, video 8]
]


    #notebox("Note", rgb("#8a94a6"), rgb("#556666"), rgb("#f7f8fa"))[
#emph[Applying join() method on list of string values]
]


  
  #notebox("Note", rgb("#8a94a6"), rgb("#556666"), rgb("#f7f8fa"))[
#emph[Unique and comma-separated words]


    Write a program that accepts a comma-separated sequence of words as input, and prints words in separate lines. Ex: Given the string "happy,smiling,face", the output would be:


    
    happy
    smiling
    face
    s = "happy,smiling,face"
]


  #notebox("Note", rgb("#8a94a6"), rgb("#556666"), rgb("#f7f8fa"))[
#emph[Lunch order]


    Use the join() method to repeat back a user's order at a restaurant, separated by commas. The user will input each food item on a separate line. When finished ordering, the user will enter a blank line. The output depends on how many items the user orders:


    - If the user inputs nothing, the program outputs: #linebreak() 
    You ordered nothing.
- If the user inputs one item (Ex: eggs), the program outputs: #linebreak() 
    You ordered eggs.
- If the user inputs two items (Ex: eggs, ham), the program outputs: #linebreak() 
    You ordered eggs and ham.
- If the user inputs three or more items (Ex: eggs, ham, toast), the program outputs: #linebreak() 
    You ordered eggs, ham, and toast.


    In the general case with three or more items, each item should be separated by a comma and a space. The word "and" should be added before the last item.


    \# Keep reading/storing input until a blank line.
food = \[\]
while True:
    line = input()
    if line == "":
        break
    food.append(line)

\# Repeat back the order, separated by commas.
if len(food) == 0:
    print("You ordered nothing")
]