python revise.txt

Q1) zip vs enumerate
zip and enumerate are both built-in functions in Python that serve different purposes.

zip function:

zip takes two or more iterables as input and returns an iterator that generates tuples containing elements from the input iterables, paired together.

Example:

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list1 = [1, 2, 3]
list2 = ['a', 'b', 'c']

zipped = zip(list1, list2)
result = list(zipped)

print(result)  # Output: [(1, 'a'), (2, 'b'), (3, 'c')]
zip stops creating tuples when the shortest input iterable is exhausted.

enumerate function:

enumerate is used to iterate over a sequence (such as a list) while keeping track of the index of the current item.

Example:

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my_list = ['apple', 'banana', 'orange']

for index, value in enumerate(my_list):
    print(index, value)

# Output:
# 0 apple
# 1 banana
# 2 orange
You can also specify a start value for the index using the start parameter of enumerate.

In summary:

Use zip when you want to combine elements from two or more iterables into tuples.
Use enumerate when you want to iterate over elements of a sequence while keeping track of their indices.


# create a list of names 
names = ['sravan', 'bobby', 'ojaswi', 'rohith', 'gnanesh'] 
  
# create a list of subjects 
subjects = ['java', 'python', 'R', 'cpp', 'bigdata'] 
  
# create a list of marks 
marks = [78, 100, 97, 89, 80] 
  
# use enumerate() and zip() function 
# to iterate the lists 
for i, (names, subjects, marks) in enumerate(zip(names, subjects, marks)): 
    print(i, names, subjects, marks)