I found something a bit weird when playing with lists. I usually use print() to debug or understand how things work but in this case the print() outputs are not helping me at all.
Here is a simple code, you will quickly see what I'm talking about:
a = [[]] * 5
b = [[]] * 5
b[0] = []
b[1] = []
b[2] = []
b[3] = []
b[4] = []
# It prints the same thing:
print(a) # [[], [], [], [], []]
print(b) # [[], [], [], [], []]
a[0] += ["test"]
b[0] += ["test"]
# Different results:
print(a) # [['test'], ['test'], ['test'], ['test'], ['test']]
print(b) # [['test'], [], [], [], []]
I was expecting a to behave like b, but it doesn't. Can someone explain this?