如何从Python中的列表计算项目？

Question

New here and in the process of learning Python.

I am running through a scenario of taking office temperatures for the day. Anything above 16 is placed into a second list where I would like to work out the percentages. For example; 5 / 8 * 100 = 62%

Here is what I currently have:

# List of temperatures taken from the office
list_temp = [16, 32, 5, 40, 10, 19, 38, 15]

# Output list above 16 degree celsius
output = []
total_output = 0

for position in list_temp:
    if position >= 16:
        output = output + [position]

print('Printing list of Temp Above 16', output)

Now my question is, and believe me I have Googled the life out of this the past couple days. How do I take the "output" list and do the percentage formula as above?

I have tried to create it in the for loop but to no avail.

Answer 1

You can use len() to get the number of items in both lists and calculate a percentage from that.

>>>print('Percentage: ' + str(len(output)/len(list_temp)*100) + '%')
Percentage: 62.5%

Answer 2

Use the list comprehension to build your list with elements:

list_temp = [16, 32, 5, 40, 10, 19, 38, 15]

lower = [i for i in list_temp if i >= 16] #your second list

percentage = len(lower)/len(list_temp) * 100
percentage
>>62.5

Then just get the percentage from the lengths.

Answer 3

To create the list with only temps greater than 16, the easiest way is to use a list comprehension:

output = [temp for temp in list_temp if temp >= 16]

The above is equivalent to:

output = []
for temp in list_temp:
    if temp >= 16:
        output.append(temp)

Then, to get the ratio:

percentage = len(output) / len(list_temp) * 100
print(percentage) # 62.5