如何计算python中列表元素的平均值？

Question

I'd like to calculate average of each values in a list. To do so, I wrote a function which gets list as parameter and calculate the average and returns the list of average again.

Here is the signal:

random_data = [10 * random.uniform(0,1) for i in range(1000)]
random_peak = [100 * random.uniform(0,1) for i in range(50)] + [0] * 950
random.shuffle(peak)
for i in range(0, len(signal)):
    signal = [peak[x] + random_data[x] for x in range(len(random_data))]

And now, I'd like to calculate m as following.

'''
m1 = 1/(number of signal) * x1
m2 = 1/(number of signal) * (x1+x2)
m3 = 1/(number of signal) * (x1+x2+x3)
...
'''

I wrote a following function to calculate m. How would I change the function to return list of ms?

def mean_values(s):
    for i in range(len(s)):
        m[i] = 1/len(s)*s[i]
    return m[i]

mean_values(signal)
#mean_values(np.array(signal)

Answer 1

use m as a float instead of list it make more sense to get mean

s = 1 / n * Σxi

you can use this to get new mean from a previous one

s' = s + (x1 - s) / n1

where s is the lastest mean, x1 the new value and n1 the new length However in numpy their is a prebuilt function np.mean() which do that and manage python list too