It sometimes reverse when I turn a string into a set
Question:
The string is:
x = 'ABBA'
whenever I use this code:
x = 'ABBA' x = ''.join(set(x)) print(x)
It results in:
BA
but I want it to be the first letters instead of the second letters:
AB
Is there any way that I can do it without using reverse function?
Answers:
Sets are unordered. so try this.
from collections import Counter
x = 'ABBA'
x = "".join(Counter(x).keys())
print(x) # AB
Sets in Python are still unordered unfortunately. However, dictionaries in newer versions of Python already preserve insertion order.
You can take advantage of this, by defining a dictionary with empty values, such that you can extract the keys in insertion order:
x = 'ABBA'
x = "".join({k:None for k in x}.keys())
print(x)
# AB
The idea is a bit hacky, but it works for now. Maybe in the future sets will also respect insertion order.
The string is:
x = 'ABBA'
whenever I use this code:
x = 'ABBA' x = ''.join(set(x)) print(x)
It results in:
BA
but I want it to be the first letters instead of the second letters:
AB
Is there any way that I can do it without using reverse function?
Sets are unordered. so try this.
from collections import Counter
x = 'ABBA'
x = "".join(Counter(x).keys())
print(x) # AB
Sets in Python are still unordered unfortunately. However, dictionaries in newer versions of Python already preserve insertion order.
You can take advantage of this, by defining a dictionary with empty values, such that you can extract the keys in insertion order:
x = 'ABBA'
x = "".join({k:None for k in x}.keys())
print(x)
# AB
The idea is a bit hacky, but it works for now. Maybe in the future sets will also respect insertion order.