I want to make list data to string. My list data like this :
[['data1'],['data2'],['data3']]
I want to convert to string like this :
"[data1] [data2] [data3]"
I try to use join like this :
data=[['data1'],['data2'],['data3']]
list=" ".join(data)
But get error like this :
string= " ".join(data)
TypeError: sequence item 0: expected string, list found
Can somebody help me?
Depending on how closely you want the output to conform to your sample, you have a few options, show here in ascending order of complexity:
>>> data=[['data1'],['data2'],['data3']]
>>> str(data)
"[['data1'], ['data2'], ['data3']]"
>>> ' '.join(map(str, data))
"['data1'] ['data2'] ['data3']"
>>> ' '.join(map(str, data)).replace("'", '')
'[data1] [data2] [data3]'
Keep in mind that, if your given sample of data doesn't match your actual data, these methods may or may not produce the desired results.
Have you tried?
data=[['data1'],['data2'],['data3']]
t = map(lambda x : str(x), data)
print(" ".join(t))
Live demo - https://repl.it/BOaS
lambda x : str(x) rather than just str?
In Python 3.x , the elements of the iterable for str.join() has to be a string .
The error you are getting - TypeError: sequence item 0: expected string, list found - is because the elements of the list you pass to str.join() is list (as data is a list of lists).
If you only have a single element per sublist, you can simply do -
" ".join(['[{}]'.format(x[0]) for x in data])
Demo -
>>> data=[['data1'],['data2'],['data3']]
>>> " ".join(['[{}]'.format(x[0]) for x in data])
'[data1] [data2] [data3]'
If the sublists can have multiple elements and in your output you want those multiple elements separated by a , . You can use a list comprehension inside str.join() to create a list of strings as you want. Example -
" ".join(['[{}]'.format(','.join(x)) for x in data])
For some other delimiter other than ',' , use that in - '<delimiter>'.join(x) .
Demo -
>>> data=[['data1'],['data2'],['data3']]
>>> " ".join(['[{}]'.format(','.join(x)) for x in data])
'[data1] [data2] [data3]'
For multiple elements in sublist -
>>> data=[['data1','data1.1'],['data2'],['data3','data3.1']]
>>> " ".join(['[{}]'.format(','.join(x)) for x in data])
'[data1,data1.1] [data2] [data3,data3.1]'
>>> import re
>>> l = [['data1'], ['data2'], ['data3']]
>>> s = ""
>>> for i in l:
s+= re.sub(r"\'", "", str(i))
>>> s
'[data1][data2][data3]'
How about this?
data = [['data1'], ['data2'], ['data3']]
result = " ".join('[' + a[0] + ']' for a in data)
print(result)
How about this:
In [13]: a = [['data1'],['data2'],['data3']]
In [14]: import json
In [15]: temp = " ".join([json.dumps(x) for x in a]).replace("\"", "")
In [16]: temp
Out[16]: '[data1] [data2] [data3]'
Try the following. This can also be achieved by "Reduce":
from functools import reduce
data = [['data1'], ['data2'], ['data3']]
print(list(reduce(lambda x,y : x+y, data)))
output: ['data1', 'data2', 'data3']
datadoes not contain strings? In fact, it contains lists. You canjoinstrings, but not lists. Try another approach with that fact in mind.