Help please!!
I was trying to create a column 'Segment' based on the condition:
if 'Pro_vol' >1 and 'Cost' >=43 then append 1
if 'Pro_vol' ==1 and 'Cost' >=33 then append 1
or append 0
Below is the code for data:
df = pd.DataFrame({'ID':[1,2,3,4,5,6,7,8,9,10],
'Pro_vol':[1,2,3,1,5,1,2,1,4,5],
'Cost' : [12.34,13.55,34.00, 19.15,13.22,22.34,33.55,44.00, 29.15,53.22]})
I tried a code:
Segment=[]
for i in df['Pro_vol']:
if i >1:
Segment.append(1)
for j in df['Cost']:
if j>=43:
Segment.append(1)
elif i==1:
Segment.append(1)
elif j>=33:
Segment.append(1)
else:
Segment.append(0)
df['Segment']=Segment
And it was giving me an error:
ValueError: Length of values does not match length of index
I don't know any other way to try to find an answer!!
You may consider np.where
np.where(((df.Cost>=33)&(df.Pro_vol==1))|((df.Cost>=43)&(df.Pro_vol>1)),1,0)
Out[538]: array([0, 0, 0, 0, 0, 0, 0, 1, 0, 1])
Related
Let's say i have a list [10,9,8,7]
and i have a my_dict {4:0, 3: 0, 2: 0 , 1 : 0}
I'm new to Python and I've tried researching how to go about this but I still could not find an answer. I want to add the list to the values of my_dict, how should I approach this?
my_list = [10,9,8,7]
my_dict = {4:0, 3: 0, 2: 0 , 1 : 0}
Is this what you're looking for
for index, (key,value) in enumerate(my_dict.items()):
my_dict[key] = my_list[index]
print(my_dict)
I'm trying to count the number of times a specific number appears in serval lists vertically.
My code:
import csv
with open('Superheroes.csv', 'r') as csvfile:
first_line = csvfile.readline()
super_reader = csv.reader(csvfile, delimiter=',')
result = []
for vote in super_reader:
vote.pop(0)
result.append([int(x) if x else 0 for x in vote])
result = [vote.count(1) for i in zip(*result)]
print(result)
example picture
So from the example picture, say I wanted to know how many times the number 11 appeared in every column of all the lists. I would expect an output of [0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 4, 2]
Thanks
You can use sum with a generator expression that outputs whether each item in a column matches the target number to perform the counting after transposing the rows into columns with zip:
def count(rows, num):
return [sum(i == num for i in map(int, col)) for col in zip(*rows)]
so that given the content of test.csv as follows:
2,1,3
3,2,1
1,3,3
1,3,2
count(csv.reader(open('test.csv')), 3) would return:
[1, 2, 2]
Demo: https://repl.it/#blhsing/IllAffectionateQuarks#main.py
I need to make a function which would compare each value in a list and then set each value accordingly. Code follows:
actions = [0, 0, 0, 0.5, 0, 0.3, 0.8, 0, 0.00000000156]
def treshold(element, value):
if element >= value:
element == 1
else:
element == 0
treshold(actions, 0.5)
This code however results in the following error:
TypeError: '>=' not supported between instances of 'list' and 'float'
I understand what this error says, however I do not know how to fix that.
A compact way of doing this, as pointed out by user202729 is with a list comprehension. The key is, you need to do this for each entry into the list. If you want to run it on the whole list at once, you could consider using numpy
actions = [0, 0, 0, 0.5, 0, 0.3, 0.8, 0, 0.00000000156]
def treshold(element, value):
thresholded_list = [int(a>=value) for a in actions]
return thresholded_list
this function is essentially a shorthand for
def treshold_long(element_list, value):
thresholded_list = []
for element in element_list:
if element >= value:
thresholded_list.append(1)
else:
thresholded_list.append(0)
return thresholded_list
Thanks to user202729 I have discovered list comprehensions.
actions = [0, 0, 0, 0.5, 0, 0.3, 0.8, 0, 0.00000000156]
treshold = 0.5
actions = [1 if i>=treshold else 0 for i in actions]
print(actions)
This basically solves my problem. I also thank to user3235916 for a valid function.
Q)After executing the code Need to print the values [1, 12, 123, 2, 23, 3, 13], but iam getting [1, 12, 123, 2, 23, 3]. I have missing the letter 13. can any one tell me the reason to overcome that error?
def get_all_substrings(string):
length = len(string)
list = []
for i in range(length):
for j in range(i,length):
list.append(string[i:j+1])
return list
values = get_all_substrings('123')
results = list(map(int, values))
print(results)
count = 0
for i in results:
if i > 1 :
if (i % 2) != 0:
count += 1
print(count)
Pretty straight forward issue in your nested for loops within get_all_substrings(), lets walk it!
You are iterating over each element of your string 123:
for i in range(length) # we know length to be 3, so range is 0, 1, 2
You then iterate each subsequent element from the current i:
for j in range(i,length)
Finally you append a string from position i to j+1 using the slice operator:
list.append(string[i:j+1])
But what exactly is happening? Well we can step through further!
The first value of i is 0, so lets skip the first for, go to the second:
for j in range(0, 3): # i.e. the whole string!
# you would eventually execute all of the following
list.append(string[0:0 + 1]) # '1'
list.append(string[0:1 + 1]) # '12'
list.append(string[0:2 + 1]) # '123'
# but wait...were is '13'???? (this is your hint!)
The next value of i is 1:
for j in range(1, 3):
# you would eventually execute all of the following
list.append(string[1:1 + 1]) # '2'
list.append(string[1:2 + 1]) # '23'
# notice how we are only grabbing values of position i or more?
Finally you get to i is 2:
for j in range(2, 3): # i.e. the whole string!
# you would eventually execute all of the following
list.append(string[2:2 + 1]) # '3'
I've shown you what is happening (as you've asked in your question), I leave it to you to devise your own solution. A couple notes:
You need to look at all index combinations from position i
Dont name objects by their type (i.e. dont name a list object list)
I would try something like this using itertools and powerset() recipe
from itertools import chain, combinations
def powerset(iterable):
s = list(iterable)
return chain.from_iterable(combinations(s, r) for r in range(len(s) + 1))
output = list(map(''.join, powerset('123')))
output.pop(0)
Here is another option, using combinations
from itertools import combinations
def get_sub_ints(raw):
return [''.join(sub) for i in range(1, len(raw) + 1) for sub in combinations(raw, i)]
if __name__ == '__main__':
print(get_sub_ints('123'))
>>> ['1', '2', '3', '12', '13', '23', '123']
I need your help to fix my code. I try to append a value to a list in a dictionary.
def distance(x1, y1, x2, y2):
dis=((x1-x2)**2) + ((y1-y2)**2)
return dis
def cluster_member_formation2(arrCH, arrN, k):
dicCH = dict.fromkeys(arrCH,[])
arrE = []
for j in range(len(arrCH)):
d_nya = distance(arrN[1][0], arrN[1][1], arrN[arrCH[j]][0], arrN[arrCH[j]][1])
arrE.append(d_nya)
minC = min(arrE)
ind = arrE.index(minC)
x = arrCH[ind]
dicCH[x].append(1)
print(arrE, minC, ind, x, dicCH)
arrCH=[23, 35]
arrN={0:[23, 45, 2, 0], 1:[30,21,2,0], 23:[12, 16, 2, 0], 35:[48, 77, 2, 0]}
cluster_member_formation2(arrCH, arrN, 1)
The output:
[349, 3460] 349 0 23 {35: [1], 23: [1]}
I try to calculate the distance between node 1 and all node in arrCH, and then take the minimum distance. In the output show the result of arrE is [349, 3460], so the minimum is 349. 349 has index 0, then I find arrCH with index 0, likes arrCH[0]=23. Finally, I want update dicCH[23].append(1) so the result is
{35: [], 23: [1]}
But, why my code update the all keys, 35 and 23?
I hope someone can help me.
Thank you..
classmethod fromkeys(seq[, value])
Create a new dictionary with keys
from seq and values set to value.
All of your dictionary values reference the same single list instance ([]) which you provide as a value to the fromkeys function.
You could use dictionary comprehension as seen in this answer.
dicCH = {key: [] for key in arrCH}