> For the complete documentation index, see [llms.txt](https://george-jen.gitbook.io/data-science-with-apach-spark/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://george-jen.gitbook.io/data-science-with-apach-spark/untitled-32.md).

# index

mutable, dictionary can be modified.

Dicitonary is a collection of key value pairs, for example: {‘a’:1,’b’:2,’c’:3}

Dicitonary keys is a sequence, iterable

d={‘a’:1,’b’:2,’c’:3}

for i in d.keys():

```
print\(i\)
```

d\[‘a’] is 1, d\[‘b’] is 2, d\[‘c’] is 3

Convert to List, use function dict()

d=dict(a=1,b=2,c=3)

Above is the same as

d={‘a’:1,’b’:2,’c’:3}

Dictionary is an object, meaning it has methods and attributes that can be invoked

To see all methods, type

help(\<dictionary variable>)

In Jupyter notebook, to see list of methods or attributes

Press shift key after enter \<tuple variable>.