How to "push" a tuple in one line of code?-CodePudding

Why can I not replace the following first code:

def conversion7(x,k):
    l=list(x)
    l.append(k)
    return tuple(l)

t=(1,2,3,4)
print(conversion7(t,7))

With the second one:

def conversion7(x,k):
    return tuple(list(x).append(k))

t=(1,2,3,4)
print(conversion7(t,7))

The first code works. Here is the compiler output of the second code:

Traceback (most recent call last):
  File "<string>", line 5, in <module>
File "<string>", line 2, in conversion7
TypeError: 'NoneType' object is not iterable
>

The purpose of the codes is to push a tuple by converting it to a list, pushing the list and then converting that back to a tuple.

CodePudding user response：

Since append does not return a reference to the list, as chepner has pointed out, you could do the following:

def conversion7(x,k):
    return tuple(list(x)   [k])

Or skip list conversion and immediately add tuples:

def conversion7(x,k):
    return x   (k,)