Why does my list have extra double brackets?
Question:
arr_list = []
arr = ['5', '6', '2', '4', '+']
arr_list.append([''.join(arr[0:4])])
print(arr_list)
Ouput: [['5624']]
Why does the output have 2 sets of square brackets? I only want one.
Thanks in advnace.
Answers:
Use:
arr_list.append(''.join(arr[0:4]))
You’re appending a list to arr_list.
Use this instead:
arr_list.append(''.join(arr[0:4]))
arr_list = []
arr = ['5', '6', '2', '4', '+']
arr_list.append(''.join(arr[0:4]))
print(arr_list)
simply remove the brackets from the third row
Remove the brackets around what you are appending:
>>> arr_list = []
>>> arr = ['5', '6', '2', '4', '+']
>>> arr_list.append(''.join(arr[0:4]))
>>> arr_list
['5624']
Or you could use list.extend rather than list.append:
>>> arr_list = []
>>> arr = ['5', '6', '2', '4', '+']
>>> arr_list.extend([''.join(arr[0:4])])
>>> arr_list
['5624']
Use
arr_list.append(''.join(arr[0:4]))
or
print(''.join(arr[0:4]))
arr_list = []
arr = ['5', '6', '2', '4', '+']
arr_list.append([''.join(arr[0:4])])
print(arr_list)
Ouput: [['5624']]
Why does the output have 2 sets of square brackets? I only want one.
Thanks in advnace.
Use:
arr_list.append(''.join(arr[0:4]))
You’re appending a list to arr_list.
Use this instead:
arr_list.append(''.join(arr[0:4]))
arr_list = []
arr = ['5', '6', '2', '4', '+']
arr_list.append(''.join(arr[0:4]))
print(arr_list)
simply remove the brackets from the third row
Remove the brackets around what you are appending:
>>> arr_list = []
>>> arr = ['5', '6', '2', '4', '+']
>>> arr_list.append(''.join(arr[0:4]))
>>> arr_list
['5624']
Or you could use list.extend rather than list.append:
>>> arr_list = []
>>> arr = ['5', '6', '2', '4', '+']
>>> arr_list.extend([''.join(arr[0:4])])
>>> arr_list
['5624']
Use
arr_list.append(''.join(arr[0:4]))
or
print(''.join(arr[0:4]))