Question

我在csv中创建一个新列（名称：Account），然后尝试创建一个序列（c = float（a）+ float（b）），并为序列中的每个数字附加到csv中的原始行，这是新列的值。这是我的代码：

%%

csv是这样的：

# -*- coding: utf-8 -*-
import csv
with open('./tradedate/2007date.csv') as inf:
reader = csv.reader(inf)
all = []
row = next(reader)
row.append('Amount')
all.append(row)

a =50 
for i, line in enumerate(inf):
    if i != 0:
        size = sum(1 for _ in inf) # count the line number

        for b in range(1, size+1): 
            c = float(a) + float(b) # create the sequence: in 1st line add 1, 2nd line add 2, 3rd line add 3...etc

            line.append(c) # this is the error message: AttributeError: 'str' object has no attribute 'append'
            all.append(line)

with open('main_test.csv', 'w', newline = '') as new_csv:
    csv_writer = csv.writer(new_csv)
    csv_writer.writerows(all)

错误讯息是：

日期,成交股數,成交金額,成交筆數,發行量加權股價指數,漲跌點數,Account
96/01/02,"5,738,692,838","141,743,085,172","1,093,711","7,920.80",97.08,51
96/01/03,"5,974,259,385","160,945,755,016","1,160,347","7,917.30",-3.50,52
96/01/04,"5,747,756,529","158,857,947,106","1,131,747","7,934.51",17.21,53
96/01/05,"5,202,769,867","143,781,214,318","1,046,480","7,835.57",-98.94,54
96/01/08,"4,314,344,739","115,425,522,734","888,324","7,736.71",-98.86,55
96/01/09,"4,533,381,664","120,582,511,893","905,970","7,790.01",53.30,56

非常感谢您的帮助!!

Answer 1

我有点困惑为什么你以这种方式构建你的代码，但最简单的解决方法是更改附加（因为你不能附加到字符串）到+ =一个字符串c的版本，即

line += str(c)

或

line += ',{}'.format(c)

（如果您需要逗号，我根据您的编写方式不清楚）

最大的问题是你没有使用你的csv阅读器 - 下面是一个更好的实现。使用csv阅读器，您可以更轻松地执行您想要执行的追加而不是直接使用文件对象。

import csv

with open('./tradedate/2007date.csv') as old_csv:
    with open('main_test.csv', 'w') as new_csv:
        writer = csv.writer(new_csv, lineterminator='\n')
        reader = csv.reader(old_csv)

        all = []
        row = next(reader)
        row.append('Line Number')
        all.append(row)

        line_number = 51
        for row in reader:
            row.append(line_number)
            all.append(row)
            line_number += 1

        writer.writerows(all)

如何修复有关在行中附加数字的代码？

1 个答案: