Python – Remove leading 0 from Strings List

Sometimes, while working with Python, we can have a problem in which we have data in which we need to perform processing and then pass the data forward. One way to process is to remove a stray 0 that may get attached to a string while data transfer. Lets discuss certain ways in which this task can be performed.

Method #1 : Using lstrip() + list comprehension
This is one of the one liner with the help of which this task can be performed. In this, we strip the leading 0 using lstrip and the extension of logic to list is done using list comprehension.

# Python3 code to demonstrate
# Remove leading 0 from Strings List
# using lstrip() + list comprehension

# Initializing list
test_list = ['012', '03', '044', '09']

# printing original list
print("The original list is : " + str(test_list))

# Remove leading 0 from Strings List
# using lstrip() + list comprehension
res = [ele.lstrip('0') for ele in test_list]

# printing result
print ("The string list after leading 0 removal : " + str(res))

Output :

The original list is : ['012', '03', '044', '09']
The string list after leading 0 removal : ['12', '3', '44', '9']

Method #2 : Using startswith() + loop + list slicing
This is one of the way in which this task can be performed. In this, we check for initial 0 using startswith() and then list slicing is used to remake string excluding 0.

# Python3 code to demonstrate
# Remove leading 0 from Strings List
# using startswith() + loop + list slicing

# Initializing list
test_list = ['012', '03', '044', '09']

# printing original list
print("The original list is : " + str(test_list))

# Remove leading 0 from Strings List
# using startswith() + loop + list slicing
for idx in range(len(test_list)):
    if test_list[idx].startswith('0'):
        test_list[idx] = test_list[idx][1:]

# printing result
print ("The string list after leading 0 removal : " + str(test_list))

Output :

The original list is : ['012', '03', '044', '09']
The string list after leading 0 removal : ['12', '3', '44', '9']