CODEWITHSUNDEEP
python
user5382
user5382

Reputation: 11

What is the purpose of the [1] in this list in a list?

I'm self-learning Python and ran into a problem I'm having difficulty with.

I'm working with Paul Barry's Headfirst Python.

The list is as follows:

movies = [
    "The Holy Grail",
    1975,
    "Terry Jones & Terry Gilliam",
    91,
    [
        "Graham Chapman",
        [
            "Michael Palin",
            "John Cleese",
            "Terry Gilliam",
            "Eric Idle",
            "Terry Jones",
        ],
    ],
]

The code is 

print(movies[4][1][3])

to generate Eric Idle. Yet, I'm unsure what the purpose of the [1] is here, and how the count generated the response.

Thanks for any help in advance.

Upvotes: 1

Views: 91

Answers (2)

DirtyBit
DirtyBit

Reputation: 16772

Since it a nested list, Indexing comes in handy:

Indexing starts from 0, and not 1.

movies = ["The Holy Grail", 1975, "Terry Jones & Terry Gilliam", 91, ["Graham Chapman", ["Michael Palin", "John Cleese", "Terry Gilliam", "Eric Idle", "Terry Jones"]]]

Elaborated:

print(movies[4])

Would give you the 4th element which is a nested list

print(movies[4][1])

Would give you the 1st element of that nested list movies[4], which is a list

print(movies[4][1][3])

Would give you the 3rd element of that list movies[4][1], which is a str

Hence:

print(movies[4])   # ["Graham Chapman", ["Michael Palin", "John Cleese", "Terry Gilliam", "Eric Idle", "Terry Jones"]]

print(movies[4][1])   # ['Michael Palin', 'John Cleese', 'Terry Gilliam', 'Eric Idle', 'Terry Jones']

print(movies[4][1][3])   # Eric Idle

Upvotes: 2

chepner
chepner

Reputation: 531055

Let's restructure the definition a little, adding comments on the right indicating the indexes:

movies = [
    "The Holy Grail",                   # [0]
    1975,                               # [1]
    "Terry Jones & Terry Gilliam",      # [2]
    91,                                 # [3]
    [                                   # [4]-begin
        "Graham Chapman",               # [4][0]
        [                               # [4][1]-begin
            "Michael Palin",            # [4][1][0]
            "John Cleese",              # [4][1][1]
            "Terry Gilliam",            # [4][1][2]
            "Eric Idle",                # [4][1][3]
            "Terry Jones"               # [4][1][4]
        ]                               # [4][1]-end
    ]                                   # [4]-end
]

movies[4] is a list. movies[4][0] is "Graham Chapman", and movies[4][1] is another list, which has "Eric Idle" at index 3.

Upvotes: 3

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