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次の例は、DataFrame で NaN 列を作成する方法を示しています。

import pandas as pd
import numpy as np
import math
import copy
import datetime as dt

"""
Accepts a list of symbols along with start and end date
Returns the Event Matrix which is a pandas Datamatrix
Event matrix has the following structure :
    |IBM |GOOG|XOM |MSFT| GS | JP |
(d1)|nan |nan | 1  |nan |nan | 1  |
(d2)|nan | 1  |nan |nan |nan |nan |
(d3)| 1  |nan | 1  |nan | 1  |nan |
(d4)|nan |  1 |nan | 1  |nan |nan |
...................................
...................................
Also, d1 = start date
nan = no information about any event.
1 = status bit(positively confirms the event occurence)
"""

def find_events(ls_symbols, d_data):
    ''' Finding the event dataframe '''
    df_close = d_data['actual_close']
    ts_market = df_close['SPY']

    print "Finding Events"

    # Creating an empty dataframe
    df_events = copy.deepcopy(df_close) # type <class 'pandas.core.frame.DataFrame'>
    df_events = df_events * np.NAN # << why it works here

次のようにメソッドを複製しようとします。

import numpy as np
import pandas as pd
from pandas import Series, DataFrame

data = {'state': ['Ohio', 'Ohio', 'Ohio', 'Nevada', 'Nevada'],
        'year': [2000, 2001, 2002, 2001, 2002],
        'pop': [1.5, 1.7, 3.6, 2.4, 2.9]}
frame = DataFrame(data)
frame = frame * np.NAN # TypeError: can't multiply sequence by non-int of type 'float'

Q> 今ここで機能しないのはなぜですか?

4

2 に答える 2

2

文字列stateを含む列があり、文字列に a を掛けるとNaNエラーが発生するためです。本当に状態を に設定したい場合はNaN、 を使用してframe['state'] = np.NANください。

于 2013-03-22T17:04:37.270 に答える