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 got SyntaxError while building simple function
#1
Hi guys,

How can i set up simple function to unpack a list?

i was trying to:
def list_to_string(x):
    x = *x
    return x
but then i can see
SyntaxError: can't use starred expression here
Quote
#2
What should this * expression do?

What do you want to achieve?
If you want to concatenate the items in the list to a str, you could use the join method on str.

your_list = ['Hello', 'World']
the_seperator = " "
my_new_str = the_seperator.join(your_list)
print(my_new_str)
Usually it's written more dense:
my_new_str = " ".join(your_list)
If the list does not only contain str objects, you need to convert them.

your_list = ['Hello', 'World', None, True, False, ...]
the_seperator = " "
to_str = map(str, your_list)
# lazy evaluation
# apply str(item) for each item in your_list
my_new_str = the_seperator.join(to_str)
print(my_new_str)

Unpacking arguments in function signature:
def greet(greeting, times, *names):
    for name in names:
        for _ in range(times):
            print(greeting.format(name))


greet("Hello {}.", 2, "zarize", "DeaD_EyE")
#                     ^^^^^^^^^^^^^^^^^^^^^ <- *names

Unpacking keyword arguments in function signature:
def cook(**indigrents):
    for indigrent, how_often in indigrents.items():
        print(indigrent.capitalize(), 'x', how_often)


cook(beer=3, bannana=1)
#     ^^^^^^^^^^^^^^^^ <- **indigrents
zarize likes this post
My code examples are always for Python >=3.6.0
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Quote
#3
Thank you for your input :)

My goal was to create simple function which would transfer list into a string ideally (just by passing an argument to function and it would return whole list as string)

Lets say i have
mylist = [ABC, 123, 456] 
Ideally i would like to get '123456'

I know that i can do it on many ways such as:
mylist = mylist.split()[1:3]
mylist = ''.join(mylist)
or:
mylist = mylist[1] + mylist[2]
SOLVED:

Usually it's written more dense:
Python Code: (Double-click to select all)
1
my_new_str = " ".join(your_list)



Thank you.. i am dumb :P
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