Iterating through rows of a Pandas series within a function

Question

I'm writing a function part of which should iterate through the rows of a Series. The function should iterate through rows of a DataFrame column passed to it i.e. df['col'], however when I try to use .iterrows I get an error that a Series doesn't have that attribute and using .iteritems produces the error below. Are there any other ways to iterate through rows of a column? I need do be able to access the index and column value.

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

Use:

rimcol.iteritems()

Since iteritems() is a function you must include the parenthesis. Otherwise you get an instance method object instead of an iterator that is returned by that instance method.

Answer 2

None of this actually required row iteration, as Ryan G pointed out in the comments. I think this (untested!) code is equivalent.

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