Question

我正在编写一个函数部分，它应该迭代Series的行。该函数应该迭代传递给它的DataFrame列的行，即df ['col']，但是当我尝试使用.iterrows时，我得到一个Series没有的错误拥有该属性并使用.iteritems产生以下错误。有没有其他方法来遍历列的行？我需要能够访问索引和列值。

def get_RIMsin(df, obs, rimcol):
    """dataframe, obs column,rim column"""    
    maxval =df['Mmedian'].max()
    minval =df['Mmedian'].min()
    dfrange = maxval-minval
    amplitude = dfrange/2

    convert = (2*np.pi)/365
    startday = obs.idxmax().dayofyear
    sinmax = 91

    for row in rimcol.iteritems: #This is where I'd like to go through rows of a series
        diff = sinmax - startday
        adjday = row.dayofyear + diff
        adjsin = np.sin(adjday * convert)
        df['RIMsine'] = row + adjsin
    return df

get_RIMsin(sve_DOC, sve_DOC['DOC_mg/L'], sve_DOC['RIMsDOC'])

TypeError                                 Traceback (most recent call last)
<ipython-input-98-4811cbf80e78> in <module>()
     17     return df
     18 
---> 19 get_RIMsin(sve_DOC, sve_DOC['DOC_mg/L'], sve_DOC['RIMsDOC'])
     20 """get_RIM2(svv_DOC, svv_DOC['DOC_mg/L'], svv_DOC['RIMsDOC'])
     21 get_RIM2(svw_DOC, svw_DOC['DOC_filt_mg/l'], svw_DOC['RIMsDOC'])

<ipython-input-98-4811cbf80e78> in get_RIMsin(df, obs, rimcol)
     10     sinmax = 91
     11 
---> 12     for row in rimcol.iteritems:
     13         diff = sinmax - startday
     14         adjday = row.dayofyear + diff

TypeError: 'instancemethod' object is not iterable

Answer 1

使用：

rimcol.iteritems()

由于iteritems()是一个函数，因此必须包含括号。否则，您将获得实例方法对象，而不是该实例方法返回的迭代器。

Answer 2

这些实际上都不需要行迭代，正如Ryan G在评论中指出的那样。我认为这个（未经测试的！）代码是等价的。

convert = (2*np.pi)/365
sinmax = 91

def get_RIMsin(df, obs, rimcol):
    """dataframe, obs column,rim column"""    
    amplitude = df['Mmedian'].ptp()/2

    startday = obs.idxmax().dayofyear

    diff = sinmax - startday
    adjday = rimcol + diff
    adjsin = np.sin(adjday * convert)
    df['RIMsine'] = adjsin
    return df

迭代函数中的Pandas系列行

2 个答案: