CODEWITHSUNDEEP
pythonpandasnumpytuples
Justin
Justin

Reputation: 585

Converting pandas dataframe into list of tuples with index

I'm currently trying convert a pandas dataframe into a list of tuples. However I'm having difficulties getting the Index (which is the Date) for the values in the tuple as well. My first step was going here, but they do not add any index to the tuple.

Pandas convert dataframe to array of tuples

My only problem is accessing the index for each row in the numpy array. I have one solution shown below, but it uses an additional counter indexCounter and it looks sloppy. I feel like there should be a more elegant solution to retrieving an index from a particular numpy array. 

def get_Quandl_daily_data(ticker, start, end):
prices = []
symbol = format_ticker(ticker)


try:
    data = quandl.get("WIKI/" + symbol, start_date=start, end_date=end)
except Exception, e:
    print "Could not download QUANDL data: %s" % e

subset = data[['Open','High','Low','Close','Adj. Close','Volume']]

indexCounter = 0
for row in subset.values:
    dateIndex = subset.index.values[indexCounter]
    tup = (dateIndex, "%.4f" % row[0], "%.4f" % row[1], "%.4f" % row[2], "%.4f" % row[3], "%.4f" % row[4],row[5])
    prices.append(tup)
    indexCounter += 1

Thanks in advance for any help!

Upvotes: 3

Views: 7804

Answers (1)

Ami Tavory
Ami Tavory

Reputation: 76297

You can iterate over the result of to_records(index=True).

Say you start with this:

In [6]: df = pd.DataFrame({'a': range(3, 7), 'b': range(1, 5), 'c': range(2, 6)}).set_index('a')

In [7]: df
Out[7]: 
   b  c
a      
3  1  2
4  2  3
5  3  4
6  4  5

then this works, except that it does not include the index (a):

In [8]: [tuple(x) for x in df.to_records(index=False)]
Out[8]: [(1, 2), (2, 3), (3, 4), (4, 5)]

However, if you pass index=True, then it does what you want:

In [9]: [tuple(x) for x in df.to_records(index=True)]
Out[9]: [(3, 1, 2), (4, 2, 3), (5, 3, 4), (6, 4, 5)]

Upvotes: 10

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