write()接受2个位置参数，但给出了3个

Question

当我使用print()函数在屏幕上打印时，我的程序会正确地生成所需的结果：

for k in main_dic.keys():
    s = 0
    print ('stem:', k)
    print ('word forms and frequencies:')
    for w in main_dic[k]:
        print ('%-10s ==> %10d' % (w,word_forms[w]))
        s += word_forms[w]
    print ('stem total frequency:', s)
    print ('------------------------------')

不过，我想将具有确切格式的结果写入文本文件。我试过这个：

file = codecs.open('result.txt','a','utf-8')
for k in main_dic.keys():
    file.write('stem:', k)
    file.write('n')
    file.write('word forms and frequencies:n')
    for w in main_dic[k]:
        file.write('%-10s ==> %10d' % (w,word_forms[w]))
        file.write('n')
        s += word_forms[w]
    file.write('stem total frequency:', s)
    file.write('n')
    file.write('------------------------------n')
file.close()

但我得到了错误：

TypeError:write((接受2个位置参数，但有3个给定了

Answer 1

print()采用单独的参数，file.write()不采用。您可以重用print()改为写入文件：

with open('result.txt', 'a', encoding='utf-8') as outf:
    for k in main_dic:
        s = 0
        print('stem:', k, file=outf)
        print('word forms and frequencies:', file=outf)
        for w in main_dic[k]:
            print('%-10s ==> %10d' % (w,word_forms[w]), file=outf)
            s += word_forms[w]
        print ('stem total frequency:', s, file=outf)
        print ('------------------------------')

我还使用了内置的open()，在Python3中不需要使用更老、功能更差的codecs.open()。您也不需要调用.keys()，直接在字典上循环也可以。

Answer 2

file.write在只期望一个字符串参数时被赋予多个参数

file.write('stem total frequency:', s)
                                  ^

当'stem total frequency:', s被视为两个不同的参数时，会引发错误。这可以通过连接来解决

file.write('stem total frequency: '+str(s))
                                  ^

Answer 3

file.write('stem:', k)

当write只需要一个参数时，您在这一行为它提供了两个参数。相比之下，print乐于接受尽可能多的论点

file.write('stem: ' + str(k))