计算平均值并在python中进行比较

Question

I have a set of values tgat represent the number of people in a postcodd on average. These are pcode1 = 239 , pcode2 = 245 , pcode3 = 210 and pcode4 = 217 now comes the bit where I am stuck. I have assumed that the average is allpcode = 220 .

Is there a way to write a code in python such that I can compare each individual pcode to the total average? What I want to do exactly is say compare pcode1 to allpcode and if pcode1 is higher/lower than allpcode display the average from pcode1 and say that pcode1 is lower than allpcode or higher than allpcode . I'd then like to repeat for all other pcodes :)

Id like to display on screen all the averages that are lower and all averages that are higher.

So something like pcode 3 and 4 averages are lower than all pcode average and pcode 1 and 2 are higher than all p code.

Is it possible to create such a code because i have no idea how/where to start?

Answer 1

In cases like this, where you frequently want to iterate over all of a set of values, it's generally better to use a single list , dict , or other collection variable, instead of a bunch of separate variables. For example:

pcodes = {1: 239, 2: 245, 3: 210, 4: 217}

Now you can write code like this:

pcodes = {1: 239, 2: 245, 3: 210, 4: 217}
allpcode = 220

for pcode, value in pcodes.items():
    if value < allpcode:
        print('code {} is lower than allpcode'.format(pcode))
    elif value > allpcode:
        print('code {} is higher than allpcode'.format(pcode))

---

If you really want to have separate variables, you have to do more work, like this:

pcode1 = 239
pcode2 = 245
pcode3 = 210
pcode4 = 217
allpcode = 220

for i, value in enumerate((pcode1, pcode2, pcode3, pcode4)):
    if value < allpcode:
        print('code {} is lower than allpcode'.format(i + 1))
    elif value > allpcode:
        print('code {} is higher than allpcode'.format(i + 1))

Answer 2

You can use a list if you only want to match values:

>>> pcode1 = 239
>>> pcode2 = 245
>>> pcode3 = 210
>>> pcode4 = 217
>>> lis = [pcode1, pcode2, pcode3, pcode4]
>>> allpcode= 220

>>> for i,x in enumerate(lis):
    if x < allpcode:
        print "pcode{} is less than {}".format(i+1,allpcode)
    elif x > allpcode:    
        print "pcode{} is greater than {}".format(i+1,allpcode)
...         
pcode1 is greater than 220
pcode2 is greater than 220
pcode3 is less than 220
pcode4 is less than 220

Better use dictionary:

As variables are just references to values in python so you can't access a variable name. And in case you've lots of pcodes then defining a variable for each of them is bad way to solve this problem, using a dict is going to be much cleaner.

#create dictionary with keys named pcode1, pcode2,...     
>>> dic = {'pcode1':239, 'pcode2':245, 'pcode3':210, 'pcode4':217}

>>> for k,v in dic.items():
    if v < allpcode:
        print "{} is less than {}".format(k ,'allpcode')
    elif v > allpcode:    
        print "{} is greater than {}".format(k,'allpcode')
...         
pcode3 is less than allpcode
pcode2 is greater than allpcode
pcode1 is greater than allpcode
pcode4 is less than allpcode

Though dictionaries don't maintain any order, you may have to collections.OrderedDict or sorted here to get keys in a particular order.