如何在for循環中將結果寫入多個CSV文件

Question

我有

with open ('~/abc.csv', 'w') as f:
    write1 = csv.write(f)
    write1.writerow(['header1', 'header2', 'header3', 'header4'])

with open ('~/def.csv', 'w') as g:
    write2 = csv.write(g)
    write2.writerow(['header1', 'header2', 'header3', 'header4', 'header5', 'header6'])

for iteration in a_list:
    perform calculations
    result1 = ([h1, h2, h3, h4],[l1, l2, l3, l4],[m1, m2, m3, m4], ...,[])
    for pa in result1:
        write1.writerow(pa)

    def fun(result1):
        result2 = ([n1, n2, n3, n4, n5, n6],[p1, p2, p3, p4, p5, p6], [], ...[])
        for pb in result2:
             write2.writerow(pb)

期待兩個csv文件為

'header1', 'header2', 'header3', 'header4'
h1, h2, h3, h4
l1, l2, l3, l4
m1, m2, m3, m4
      :

和

'header1', 'header2', 'header3', 'header4', 'header5', 'header6'
n1, n2, n3, n4, n5, n6
p1, p2, p3, p4, p5, p6

當所有迭代都完成並且可以使用writer.writerows（pa）輕松將單獨的appended（list）result1和result2寫入單獨的文件時，可以輕松完成此操作。 但是，我想在每次迭代中都寫入csv文件，這樣我就不會因為某種原因不得不中斷循環。

謝謝！

Answer 1

您可以在上下文管理器中放置兩個文件，並具有兩個csv.writer對象（自Python 2.7起）：

with open ('~/abc.csv', 'w') as f, open ('~/def.csv', 'w') as g:
    writer1 = csv.writer(f)
    writer2 = csv.writer(g)

    writer1.writerow(['header1', 'header2', 'header3', 'header4'])    
    writer2.writerow(['header1', 'header2', 'header3', 'header4', 'header5', 'header6'])

    for iteration in a_list:
        # perform calculations
        for pa in result1:
            writer1.writerow(pa)
        for pb in result2:
            writer2.writerow(pb)

從文檔（對於python 2.7到3.5相同 ）。

如果有多個項目，則上下文管理器的處理就像嵌套了多個with語句一樣：

with A() as a, B() as b:
    suite

相當於

with A() as a:
    with B() as b:
        suite

這表明完成此操作的另一種方法是使嵌套更深一層。

with open ('~/abc.csv', 'w') as f:
    with open ('~/def.csv', 'w') as g:
        writer1 = csv.writer(f)
        writer2 = csv.writer(g)
        ...

Answer 2

當前，您僅聲明了一個writer變量。 您將需要第二個writer變量。

fWriter = csv.write(f)

...

gWriter = csv.write(g)

...

fWriter.writerow(pa)

...

gWriter.writerow(pb)