Why do I get this error: not enough values to unpack (expected 5, got 4)?

Question

Basically I want a graph with 3 subplots. The 2nd plot will be a candlestick chart and is the one I am currently working on now. However, I keep getting a "not enough values to unpack" error and I don't really know why???

start = dt.datetime(2016,1,1)
end = dt.datetime(2016,12,31)    

fig = plt.figure()
ax1 = plt.subplot2grid((6,1), (0,0), rowspan = 1, colspan = 1)
ax2 = plt.subplot2grid((6,1), (1,0), rowspan = 4, colspan = 1)
ax3 = plt.subplot2grid((6,1), (5,0), rowspan = 1, colspan = 1)

df2 = pdr.data.DataReader('TSLA', 'yahoo', startdate, enddate)
df2.drop('Adj Close', axis = 1, inplace = True)
MA20 = df2['Close'].rolling(20).mean()
MA50 = df2['Close'].rolling(50).mean()

cols = ['Open', 'High', 'Low', 'Close', 'Volume']
df2 = df2[cols] #reordering columns to OHLC order

candlestick_ohlc(ax2, df2, width=0.4, colorup='#77d879', colordown='#db3f3f')

plt.show()

I get this error:

>---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-329-f2bd49065390> in <module>
     18 df2 = df2[cols]
     19 
---> 20 candlestick_ohlc(ax2, df2, width=0.4, colorup='#77d879', colordown='#db3f3f')
     21 
     22 ax1.plot(MA20, label = '20-day')

>c:\users\cecilia\appdata\local\programs\python\python35\lib\site-packages\mpl_finance.py in candlestick_ohlc(ax, quotes, width, colorup, colordown, alpha)
    234     return _candlestick(ax, quotes, width=width, colorup=colorup,
    235                         colordown=colordown,
--> 236                         alpha=alpha, ochl=False)
    237 
    238 

>c:\users\cecilia\appdata\local\programs\python\python35\lib\site-packages\mpl_finance.py in _candlestick(ax, quotes, width, colorup, colordown, alpha, ochl)
    281             t, open, close, high, low = q[:5]
    282         else:
--> 283             t, open, high, low, close = q[:5]
    284 
    285         if close >= open:

>ValueError: not enough values to unpack (expected 5, got 4)

The chart I get also does not seem right. It's fully red, but for candlesticks that closed higher than it opened, I have set the color to be green but no green candles appear. I have arranged the columns in the 'OHLC' order to correspond with the function, so I don't know why it comes out like this too.

Please paste the full error. The error traceback will point you to the exact line causing the issue. — Error - Syntactical Remorse, Aug 08 '19 at 14:46
@ImportanceOfBeingErnest ... I feel like an idiot lol. You're right! Although... can I ask how I can fix this? Do I have to take out the index and have it as a column instead? — Hannah Tang, Aug 08 '19 at 15:48
Yes you probably need to take the index (if that is where the dates are) and also probably need to convert it to numbers via `matplotlib.dates.date2num` first. There should actually be enough examples of that around? — ImportanceOfBeingErnest, Aug 08 '19 at 18:46
@ImportanceOfBeingErnest That's what I've done. Both with date number as an index, and as a column. I've tried both date and date numbers. It doesn't work and keeps giving me the same error. Sorry for the trouble. If you replicate my code, do you get the same error? — Hannah Tang, Aug 09 '19 at 04:21

ImportanceOfBeingErnest · Answer 1 · 2019-08-11T10:42:22.223

candlestick_ohlc needs to take the date as input. Also, dates need be converted to numbers. Hence the following would work.

import datetime as dt
import matplotlib.pyplot as plt
import pandas_datareader as pdr
from mpl_finance import candlestick_ohlc
import matplotlib.dates as mdates


start = dt.datetime(2016,1,1)
end = dt.datetime(2016,12,31)    

fig, ax = plt.subplots()
df2 = pdr.data.DataReader('TSLA', 'yahoo', start, end)
df2.drop('Adj Close', axis = 1, inplace = True)

df2.reset_index(inplace=True)
df2["Date"] = mdates.date2num(df2["Date"].values)
print(df2.head())

cols = ['Date', 'Open', 'High', 'Low', 'Close', 'Volume']
df2 = df2[cols] #reordering columns to OHLC order

candlestick_ohlc(ax, df2.values, width=0.4, colorup='#77d879', colordown='#db3f3f')

ax.xaxis_date()

plt.show()

Why do I get this error: not enough values to unpack (expected 5, got 4)?

1 Answers1