python写csv文件

Python操作excel文件非常方便，可是当写入数据列数大于256列时就不支持了。所以必须写CSV替代。
在此记录一下CSV文件的写入代码，注意utf-8编码哦！

import sys
reload(sys)
sys.setdefaultencoding( "utf-8" )
import xlrd
import xlwt
import csv

file = open('my.csv', 'wb')
file.write('xEFxBBxBF');
csv_writer = csv.writer(file)

actor_book = xlrd.open_workbook("actors.xls")
actor_sheet = actor_book.sheets()[0]

actor_dic = {}
for row_index in range(0, actor_sheet.nrows):
    actor = actor_sheet.cell(row_index, 0).value
    if actor not in actor_dic.keys():
        actor_dic[actor] = {}

actor_statistics_count_book = xlrd.open_workbook("count_statistics.xlsx")
actor_statistics_count_sheet = actor_statistics_count_book.sheets()[0]
column_write = False
for actor_a in actor_dic.keys():
    csv_row_list = []
    actor_b_dic = {}
    csv_row_list.append(actor_a)
    matrix_column = 1
    csv_row_title_list = []
    csv_row_title_list.append("actors")
    for actor_b in actor_dic.keys():
        if (not column_write):
            csv_row_title_list.append(actor_b)

        matrix_count = 0
        for row_index in range(1, actor_statistics_count_sheet.nrows):
            actor1 = actor_statistics_count_sheet.cell(row_index, 0).value
            actor2 = actor_statistics_count_sheet.cell(row_index, 1).value
            if actor1 != actor_a and actor2 != actor_a:
                continue

            if actor1 != actor_b and actor2 != actor_b:
                continue

            if actor_a == actor_b and actor1 != actor2:
                continue

            matrix_count += int(actor_statistics_count_sheet.cell(row_index, 2).value)

        csv_row_list.append(matrix_count)
    if not column_write:
        csv_writer.writerow(csv_row_title_list)
    column_write = True
    csv_writer.writerow(csv_row_list)

接上篇，在运行这个文件的时候突然遇到一个莫名其妙的问题：“‘module’ object has no attribute 'writer'”，然后百度发现有哥们也遇到了相同的问题，是由于将另外的python文件命名为“csv.py”导致的！由于csv.py编译后会产生名为csv的module。而系统会默认在当前路径下去引入module，从而导致引入的此module非彼module！

以后一定要注意不能瞎起名啊。。。

。

CSV模块文档參考：http://docs.python.org/library/csv.html