How I can speed up my Cython module?

[AlekseyPython]

Python 3.7.5rc1, Cython 0.29.13

Hello, I created an ndarray in which, when reading a file line by line, I accumulate the first and last transaction price in the context of clients:

1 2	dtype=np.dtype([('client','U13'), ('day_begin','u4'), ('day_end','u4'), ('price_begin','f4'), ('price_end','f4')])   return np.empty(0, dtype=dtype)

My Cython module, in which I get the lines from the csv- file and divide them into fields and convert them to the desired values to accumulate transaction statistics:

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import numpy as np cimport numpy as np   cpdef process_string(str file_str, str mask_client, str code, int end_day_int, np.ndarray periods_clients, dict line_by_client):     if not file_str:         return False, periods_clients           cdef list fields = file_str.split(';')           cdef str client = fields[3]     if client.find(mask_client)==-1 and client!=code:         return False, periods_clients             cdef int current_date = _get_date_from_str(fields[1])     if current_date > end_day_int:         return True, periods_clients           cdef double current_price = _convert_price_to_float(fields[5])     periods_clients = _add_data_to_array(client, current_date, current_price, periods_clients, line_by_client)           return False, periods_clients   cdef double _convert_price_to_float(str price):     return np.float64(price.replace(',', '.'))    cdef int _get_date_from_str(str date_str):     return 10000*int(date_str[6:10]) + 100*int(date_str[3:5]) + int(date_str[0:2])       cdef _add_data_to_array(str client, int current_date, double current_price, np.ndarray array, dict line_by_client):         index_line = line_by_client.setdefault(client)         if index_line is None:             new_array = np.zeros(1, array.dtype)             line = new_array[0]             line['client'] = client             line['day_begin'] = current_date             line['price_begin'] = current_price             line['day_end'] = current_date             line['price_end'] = current_price                            array = np.append(array, new_array)             line_by_client[client] = len(array)-1                        else:             array[index_line]['day_end'] = current_date             array[index_line]['price_end'] = current_price                       return array

Cython version works almost at the same speed as the python one. How I can speed up this module?