Python | Ways to format elements of given list

Given a List of float values, the task is to truncate all float values to 2-decimal digit. Let’s see the different methods to do the task. 
Method #1 : Using List comprehension 

Python3

# Python code to truncate float
# values to 2-decimal digits.

# List initialization
Input = [100.7689454, 17.232999, 60.98867, 300.83748789]

# Using list comprehension
Output = ["%.2f" % elem for elem in Input]

# Printing output
print(Output)

Output:

['100.77', '17.23', '60.99', '300.84']

Method #2 : Using Map 

Python3

# Python code to truncate float
# values to 2 decimal digits.

# List initialization
Input = [100.7689454, 17.232999, 60.98867, 300.83748789]

# Using map
Output = map(lambda n: "%.2f" % n, Input)

# Converting to list
Output = list(Output)

# Print output
print(Output)

Output:

['100.77', '17.23', '60.99', '300.84']

Method #3 : Using format 

Python3

# Python code to truncate float
# values to 2 decimal digits.

# List initialization
Input = [100.7689454, 17.232999, 60.98867, 300.83748789]

# Using format
Output = ['{:.2f}'.format(elem) for elem in Input]

# Print output
print(Output)

Output:

['100.77', '17.23', '60.99', '300.84']

Method #4 : Using Iteration 

Python3

# Python code to truncate float
# values to 2 decimal digits.

# List initialization
Input = [100.7689454, 17.232999, 60.98867, 300.83748789]

# Output list initialization
Output = []

# Iterating
for elem in Input:
    Output.append("%.2f" % elem)

# Printing output
print(Output)

Output:

['100.77', '17.23', '60.99', '300.84']

Method #5 : Using reduce

• This code imports the functools module and uses its reduce function to apply a lambda function to each element in the list Input.
• The lambda function takes in 2 arguments: acc (short for accumulator) and x, and adds the string representation of x with 2 decimal points to acc.
• The initial value of acc is an empty list.
• The reduce function iteratively applies the lambda function to each element in Input, starting with the initial value of acc and the first element of Input, and then using the result of the previous iteration as the new value of acc for the next iteration.
• The final result of the reduce function is the list of strings with 2 decimal points for each element in Input.

Python3

import functools


Input = [100.7689454, 17.232999, 60.98867, 300.83748789]
#The reduce function iteratively applies the lambda function to each element in Input, starting with the initial value
#of acc and the first element of Input, and then using the result of the previous iteration as the new value of acc for the next iteration.
Output = functools.reduce(lambda acc, x: acc + ["%.2f" % x], Input, [])
print(Output)
#This code is contributed by Edula Vinay Kumar Reddy

Output

['100.77', '17.23', '60.99', '300.84']