python - CSV Python 序列错误

Question

我使用以下代码:

import csv
f = csv.writer(open("pe_ratio.csv","w"))

def factorial(n):
    results = 1
    # results are one because that is the minimum number 
    while n >= 1:
        results =  results * n
        # results * nth number of n
        n = n - 1   
        # n - 1     
        # two variables are affected in this program results and n
    return f.writerow([results])

print factorial(4)

file.close()

我收到此错误:

Traceback (most recent call last):
  File "pe_ratio.py", line 23, in <module>
    print factorial(4)
  File "pe_ratio.py", line 21, in factorial
    return f.writerows([results])
_csv.Error: sequence expected

我怀疑我需要阅读CSV documentation并深入地搞清楚这个问题。我想要完成的是让 csv 文件写入行阶乘(4)的结果。我尝试取出阶乘(4)的打印函数，但程序停止了。我在这里先向您的帮助表示感谢。

Answer 1

import csv
with open("pe_ratio.csv", "w") as out_file:
    f = csv.writer(out_file)

    def factorial(n):
        results = 1
        # results are one because that is the minimum number 
        while n >= 1:
            results =  results * n
            # results * nth number of n
            n = n - 1   
            # n - 1     
            # two variables are affected in this program results and n
        return f.writerow([results])  # <---note writerows vs writerow

    print factorial(4)