python -- read write excel

def _read_excel_file(in_file):
    trace_pos_arr = []
    data = xlrd.open_workbook(in_file)
    for table in data.sheets():
        nrows = table.nrows
        for i in range(nrows):
            if i == 0:
                continue
            row = table.row_values(i)
            # Convert all values to unicode.
            # row = map(unicode, row)
            trace_id, trace_x, trace_y, trace_z = int(row[0]), int(row[1]), int(row[2]), int(row[3])

            # yield (trace_id, trace_x, trace_y, trace_z)
            trace_pos_arr.append([trace_x, trace_y, trace_z])
    return trace_pos_arr

def _write2excel(traces, to_file):
    workbook = xlsxwriter.Workbook(to_file)
    sheet = workbook.add_worksheet()
    idx = 0
    time = 0
    idx = _write_row_in_sheet(idx, ["x", "y", "z"], sheet, time)
    for trace in traces:
        if trace is None:
            continue
        print(trace)
        print(len(trace))

        org_1 = trace[0][0]
        org_2 = trace[0][1]
        org_3 = trace[0][2]
        time = trace[0][3]
        row = [org_1, org_2, org_3]

        idx = _write_row_in_sheet(idx, row, sheet, time)
    workbook.close()

def _write2excel2(traces, to_file):
    workbook = xlsxwriter.Workbook(to_file)
    sheet = workbook.add_worksheet()
    idx = 0
    time = 0
    idx = _write_row_in_sheet(idx, ["x", "y", "z"], sheet, time)

    for trace in traces:
        row = []
        for i in range(len(trace)):
            org = trace[i]
            row.append(org)
        idx = _write_row_in_sheet(idx, row, sheet, time)
    workbook.close()

def _write2excel3(traces, to_file):
    workbook = xlsxwriter.Workbook(to_file)
    sheet = workbook.add_worksheet()
    idx = 0
    time = 0
    idx = _write_row_in_sheet(idx, ["x", "y", "z"], sheet, time)

    for trace in traces:
        print(trace)
        idx = _write_row_in_sheet2(idx, trace, sheet, time)
    workbook.close()

def _write_row_in_sheet2(row_index, trace, sheet, time, format=None):
    for j in range(len(trace)):
        row = trace[j][:3]
        time = trace[j][-1]
        for i, item in enumerate(row):
            sheet.write(row_index, time * 3 + 1 + i, round(item, 1), format)
    return row_index + 1

def _write_row_in_sheet(row_index, row, sheet, time, format=None):
    for i, item in enumerate(row):
        sheet.write(row_index, time * 3 + 1 + i, item, format)
    return row_index + 1