在迭代字典时获取无类型错误?

时间:2015-07-14 14:22:55

标签: python

代码: -

def displayHand(hand):
    for letter in hand.keys():
       for j in range(hand[letter]):
         print letter,              # print all on the same line
    print                               # print an empty line

hand = {'a':1, 'q':1, 'l':2, 'm':1, 'u':1, 'i':1}

print displayHand(hand)

输出: -

a i m l l q u
None

需求输出: -

a i m l l q u

请提供合理的解决方案。

3 个答案:

答案 0 :(得分:3)

private void IDBox_Click(object sender, EventArgs e) { CopyToClipboard((TextBox)sender); } private void CopyToClipboard(TextBox textBox) { if (textBox.Text != "") { textBox.BackColor = System.Drawing.Color.MistyRose; Clipboard.SetText(textBox.Text); // set 200ms timeout and then change BackColor //textBox.BackColor = System.Drawing.SystemColors.Window; } } 什么都不返回。只需删除代码末尾的displayHand即可。

print

输出:

def displayHand(hand):
    for letter in hand.keys():
       for j in range(hand[letter]):
         print letter,              # print all on the same line
    print                               # print an empty line

hand = {'a':1, 'q':1, 'l':2, 'm':1, 'u':1, 'i':1}

displayHand(hand)

答案 1 :(得分:1)

当您打印所打印的功能的结果时,您的功能不会return任何内容None

displayHand(hand) # execute the function without printing the result, in this case None

答案 2 :(得分:1)

displayHand()函数不返回任何内容,因此当你这样做时 -

print displayHand(hand)

这实际上会打印None,因为displayHand()没有返回任何内容。只需在没有print -

的情况下将其称为正常
displayHand(hand)