My goal: to know how many index satisfy criteria of 4<value<10 from a series object count_num.
I got the series object after df[].value_counts() like below (index of a,c,e satisfy the criteria)
index value
a 5
b 3
c 7
d 1
e 6
I tried but got error of cannot unpack non-iterable int object:
index_numb = []
for index, value in count_num:
if 4<= value <= 10:
index_numb += 1
Thank you very much for your time and comments
You could do list comprehension to create a list of all the indicies that match and get the length of that, so something like len([index for index in count_num if 4 < count_num[index] < 10])
the len() part should be self-explanatory, just getting the length of whatever's passed in but the part inside is your list comprehension:
[index for index in count_num if 4 < count_num[index] < 10]
or basically create a list of all index values where count_num[index] is between 4 and 10.
That last conditional there are a few ways you can do it, either what I put, or if you didn't think that, count_num[index] < 4 and count_num[index] < 10 or even since it's a range do something like count-num[index] in range(4,10)
with the way you're doing it though you'll run into several errors.
First, the reason it's failing is because doing for index, value in count_num, the in part uses an iterator that's returning only the keys and so it's failing. you'd need to do for index, value in count_num.items()
After you fix that, your index_numb += 1 is indented wrong so it's not considered within the scope of your if statement so you'll get an error with that.
After you fix that additionally, you're doing index_numb += 1 but index_numb is a list so adding 1 to it makes no sense. You probably meant to do index_numb = 0 then your index_numb += 1 will increment.
code:
index_numb = []
index_numb += 1
output :
Traceback (most recent call last):
File "<string>", line 3, in <module>
TypeError: 'int' object is not iterable
other code:
index_numb = []
print(index_numb, type(index_numb))
index_numb += [1]
print(index_numb, type(index_numb))
output :
[] <class 'list'>
[1] <class 'list'>
see here better exolanation:
Why does += behave unexpectedly on lists? :
When dealing with lists like you are, though, the += operator is a shorthand for someListObject.extend(iterableObject). See the documentation of extend().
I found a non-direct way to solve this problem. Expect some brief or direct methods to this!
df = series.to_frame() #convert the series object to df
df['screened_output'] = df['value'].apply(lambda x: 'true' if 4<= x <= 10 else 'false')
index_4to10 = df['screened_output'].value_counts()
Then I can see the number of index satisfied or not, from the value of true and false...
