Python 3.2 TypeError:% 不支持的操作数:'NoneType' 和 'str' [英] Python 3.2 TypeError: unsupported operands(s) for %: 'NoneType' and 'str'

问题描述

刚开始使用python并尝试了以下代码

my_name = 'Joe Bloggs'我的年龄 = 25my_height = 71 # 英寸my_weight = 203 #lbs 近似值，从 ~14.5 石头转换而来my_eyes = '蓝色'my_teeth = '白色'my_hair = '棕色'print("让我们谈谈 %s") % my_nameprint ("他有 %d 英寸高.") % my_heightprint ("他重 %d 磅.") % my_weight打印(其实还不算太重")print ("他有 %s 的眼睛和 %s 的头发.") % (my_eyes, my_hair)打印(根据咖啡的不同，他的牙齿通常是 %s.")% my_teeth

我收到第 9 行(第一个打印语句)的错误，其中说:类型错误:% 不支持的操作数:'NoneType' 和 'str'

即使尝试使用 {0} 和 .format 方法，我也无法绕过它，有什么想法吗?

解决方案

您想将右括号移到行尾:print ("He's %d inches high." % my_height)

那是因为在 Python 3 中，print 是一个函数，因此您将 % 运算符应用于打印函数的结果，即 None.您想要的是将 % 运算符应用于格式字符串和要替换的字符串，然后将该操作的结果发送到 print().>

正如 GWW 所指出的，这种字符串格式在 Python 3.1 中已被弃用.您可以在此处找到有关替换 % 运算符的 str.format 的更多信息:http://docs.python.org/library/stdtypes.html#str.format

然而，由于 Python 2.x 是大多数生产环境的规范，熟悉 % 操作符仍然很有用.

Just getting started with python and tried the following bit of code

my_name = 'Joe Bloggs'
my_age = 25
my_height = 71 # inches
my_weight = 203 #lbs approximate, converted from ~14.5 stones
my_eyes = 'Blue'
my_teeth = 'White'
my_hair = 'Brown'

print("Let's talk about %s") % my_name
print ("He's %d inches tall.") % my_height
print ("He's %d pounds heavy.") % my_weight
print ("Actually that's not too heavy")
print ("He's got %s eyes and %s hair.") % (my_eyes, my_hair)
print ("His teeth are usually %s depending on the coffee.") % my_teeth

I get an error for line 9 (the first print statement) which says: TypeError: unsupported operands(s) for %: 'NoneType' and 'str'

I haven't been able to get around it even when trying to use the {0} and .format method, any ideas?

解决方案

You want to move the close paren to the end of the line: print ("He's %d inches tall." % my_height)

That's because in Python 3, print is a function, so you are applying the % operator to the results of the print function, which is None. What you want is to apply the % operator to the format string and the string you wish to substitute, and then send the result of that operation to print().

EDIT: As GWW points out, this kind of string formatting has been deprecated in Python 3.1. You can find more information about str.format, which replaces the % operator, here: http://docs.python.org/library/stdtypes.html#str.format

However, since Python 2.x is the norm in most production environments, it's still useful to be familiar with the % operator.

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