Access violation counting occurrences

I'm getting an access violation with this python function that I'm calling to in C++. I'm trying to read a file and write a new one that will show items and count all instances of a word in the reading file and display it in the write file. I'm a little rusty with python but I'm really not sure what I'm doing wrong

  def GetHistogram(): #FIXME
     frequency = {}
     with open('input.txt','r') as itemList, open('frequency.dat','w') as frequencyFile:
        if frequencyFile.closed:
            print("file closed")

        itemString = itemList.read().lower() #reads file and sets all to lowercase to make matching easier
        matches = re.findall(r'\b[a-z]{1,25}\b', itemString) #finds all matches within boundaries
        for item in matches: # for loop to iterate over matches
            count = frequency.get(item, 0)  #using get() to return value of item
            frequency[item] = count + 1 #counts the frequency of each word in matches

        List = frequency.keys() #assigns list with keys in dictionary (items)

        for items in List:
            frequencyFile.write(items.title(), frequency[items]) #prints items (titled again) and frequency
   
     return;

Editing for C++, here are the related functions:

void displayHistogram() { //FIXME
    ifstream frequencyFile("frequency.dat");

    cout << "\n\nWriting items and quantities sold today to a file: \n\n";
    CallProcedure("GetHistogram");


    if (!frequencyFile.is_open()) {
        cout << "could not open file" << endl;
    }

    string item;
    int count;
    string histo;

    while (frequencyFile >> item >> count) {
        histo = (count * '*');
        cout << item << ": " << histo << endl;
    }

    frequencyFile.close();

   }

and CallProcedure() :

void CallProcedure(string pName)
{
    char* procname = new char[pName.length() + 1];
    std::strcpy(procname, pName.c_str());

    Py_Initialize();
    PyObject* my_module = PyImport_ImportModule("PythonCode");
    PyErr_Print();
    PyObject* my_function = PyObject_GetAttrString(my_module, procname);
    PyObject* my_result = PyObject_CallObject(my_function, NULL);
    Py_Finalize();

    delete[] procname;
}

When I build, it succeeds, so I was assuming it was on the python side. The violation I'm getting is occurring in the call procedure function :

Exception thrown at 0x1D6EC348 (python36.dll) in Groceries.exe: 0xC0000005: Access violation reading location 0x00000004.

source https://stackoverflow.com/questions/71895748/access-violation-counting-occurrences