Mohideen bin Mohammed

原因是, {} 是的语法 .format() 所以对你来说 不认识 {Hello}

可以使用双大括号{{}覆盖它,

x = " {{ Hello }} {0} "

或

尝试 %s

x = " { Hello } %s"
print x%(42)  

如果你想写一行字,

然后试试这个,

def f1(x):
    return x * 2
def f2(x):
    return x + 1

>>> out = lambda x, f=f1, f2=f2: f1(f2(x)) # a directly passing your input(1) with 2 function as an input (f1, f2) with default so you dont need to pass it as an arguments
>>> out(1)
4
>>> 

>>> def compose(f1, n):
...   def func(x):
...     while n:
...       x = f1(x)
...       n = n-1
...     return x
...   return func

>>> d = compose(f1, 2)
>>> d(2)
8
>>> d(1)
4
>>> 

两种方法,

1. 您可以使用 help()
2. 您可以使用 inspect

1)检查:

使用 输入 模块来探索您想要的代码… 注: 您只能浏览已导入的模块(aka)包的代码

例如:

  >>> import randint  
  >>> from inspect import getsource
  >>> getsource(randint) # here i am going to explore code for package called `randint`

2)帮助():

你可以简单地使用 帮助() 命令获取有关内置函数及其代码的帮助。

例如: 如果要查看str()的代码,只需键入- help(str)

它会像这样回来,

>>> help(str)
Help on class str in module __builtin__:

class str(basestring)
 |  str(object='') -> string
 |
 |  Return a nice string representation of the object.
 |  If the argument is a string, the return value is the same object.
 |
 |  Method resolution order:
 |      str
 |      basestring
 |      object
 |
 |  Methods defined here:
 |
 |  __add__(...)
 |      x.__add__(y) <==> x+y
 |
 |  __contains__(...)
 |      x.__contains__(y) <==> y in x
 |
 |  __eq__(...)
 |      x.__eq__(y) <==> x==y
 |
 |  __format__(...)
 |      S.__format__(format_spec) -> string
 |
 |      Return a formatted version of S as described by format_spec.
 |
 |  __ge__(...)
 |      x.__ge__(y) <==> x>=y
 |
 |  __getattribute__(...)
-- More  --