CODEWITHSUNDEEP
python
Pygirl
Pygirl

Reputation: 13349

How to find the maximum no of digits in the list in python

For example If the list contains numbers 3 , 14 , 24 , 6 , 157 , 132 ,12 It should give the maximum no of digits as 3

Upvotes: 2

Views: 1487

Answers (8)

Samuel.MH
Samuel.MH

Reputation: 71

The key is to treat the elements as strings so you can ask for their length or number of digits.

Some code 

#Your list
L = [ 3 , 14 , 24 , 6 , 157 , 132 ,12]

# Imperative
max_digits = 0
for element in L:
    n_digits = len(str(element))
    if n_digits > max_digits:
        max_digits = n_digits

# Funtional
max_digits = reduce(lambda x,y: x if x>y else y, map(lambda x: len(str(x)), L), 0)

Upvotes: 1

niemmi
niemmi

Reputation: 17263

In case your list contains negative numbers you could pass generator expression calling abs as an argument for max:

>>> mylist = [3, 14, 24, 6, 157, 132, 12, -100]
>>> len(str(max(abs(x) for x in mylist)))
3

Note that above only works with integers. If your list contains other types of numbers, like float or Decimal then changes are required.

Upvotes: 4

Mike Robinson
Mike Robinson

Reputation: 8945

The first requirement is to decide exactly what you mean by "number of digits." For example, -2.1352 contains ... how many digits? One? Five? Six? Seven? An argument could be made in favor of each of these.

Then, in the case of floating point numbers, there's the question of rounding. Float-binary is base-two which must be converted to base-ten at some number of digits' (decimal) precision. Is that number fixed? Would -2.3 (two digits? one? three?) be displayed as -2.3000 hence five digits (four? six?).

A "code golf" exercise like this can be tackled in any number of ways. Step-one is to hammer out exactly what you mean in your statement of the problem to be coded.

Upvotes: 2

Soumendra
Soumendra

Reputation: 1624

Try this

mylist = [3, 14, 24, 6, 157, 132, 12]
print (len(str(max([abs(element) for element in mylist]))))
#3
#This will work for negative numbers too

Upvotes: 4

Angus
Angus

Reputation: 359

"Try this

mylist = [3, 14, 24, 6, 157, 132, 12]
print (len(str(max(mylist)))

"

Sorry I would comment but < 50 rep. Credit to @soumendra

Soumendra's solution works but not for negative numbers. Easy way to do this is:

mylist = [3, 14, 24, 6, 157, 132, 12]
a = len(str(max(mylist)))
b = len(str(min(mylist)))
print max([a, b])

Upvotes: 1

harshil9968
harshil9968

Reputation: 3244

Just use :

len(str(max(list)))

what we are doing here finding the maximum number, then lenght of that.

Upvotes: 1

ynot269
ynot269

Reputation: 345

tempMaxDig = 0
for item in numList:
    num = len(str(item))
    if num > tempMaxDig:
         tempMaxDig =  num 


return tempMaxDig

Upvotes: 1

The Dude
The Dude

Reputation: 1118

Try this:

max = list[0]
for i in range(1,len(list)):
    if len(list[i]) > max:
        max = len(list[i])

Upvotes: 1

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