python学习4——提问、提示。

一、提问——打印出改变了的输出。

因为没有任何计算机基础，所以出错很多，摸索了一会。

出错1：

print("How old are you?"),
age = raw_input()
print("What is your name?"),
name = raw_input()
print("How tall are you?"),
height = raw_input()
print("So your name is %r, you are %r years old and %r tall." , %name,age,height)

 输出结果

E:abc>python 6.py
How old are you?
Traceback (most recent call last):
File "6.py", line 2, in <module>
age = raw_input()
NameError: name 'raw_input' is not defined

原因：python3中将raw_input()命令改为input()，所以不能会有未定义错误。

出错2：

print("How old are you?"),
age = input()
print("What is your name?"),
name = input()
print("How tall are you?"),
height = input()
print("So your name is %r, you are %r years old and %r tall." , %name,age,height)

输出结果

E:abc>python 6.py
File "6.py", line 7
print("So your name is %r, you are %r years old and %r tall.", %name,age,height)

^
SyntaxError: invalid syntax

原因：

%符号前面不应该有：逗号，

出错3：

print("How old are you?"),
age = input()
print("What is your name?"),
name = input()
print("How tall are you?"),
height = input()
print("So your name is %r, you are %r years old and %r tall."  %name,age,height)

输出结果

E:abc>python 6.py
How old are you?
20
What is your name?
jack
How tall are you?
189
Traceback (most recent call last):
File "6.py", line 7, in <module>
print("So your name is %r, you are %r years old and %r tall." %name,age,height)
TypeError: not enough arguments for format string

原因：

% 后定义的变量需要用()引用

最终正确的代码如下：

print("How old are you?"),
age = input()
print("What is your name?"),
name = input()
print("How tall are you?"),
height = input()
print("So your name is %r, you are %r years old and %r tall." %(name,age,height))

输出结果：

E:abc>python 6.py
How old are you?
18
What is your name?
lucy
How tall are you?
168
So your name is 'lucy', you are '18' years old and '168' tall.

二、提示

age = input("How old are you?")
name = input("What is your name?")
weight = input("How much do you weight?")
print("So your name is %r, you are %r years old and %r tall." %(name,age,weight))

 三、python -m pydoc input 查看命令。

通过cmd输入python -m pydoc input 可以查看各命令的解释。

如查看 sys 命令：