Can You Loop in Python Without an Explicit Iterator?

Looping Without Explicit Iterators in Python

In Python, the conventional way to iterate over a range of values involves using a for loop with an iterator variable, such as:

for i in range(some_number):
    # do something

However, this syntax may be redundant in cases where you don't require the iterator variable. Instead, you may wonder if it's possible to execute a loop without specifying an explicit iterator.

Answer:

Unfortunately, it is currently not feasible to create a loop without using an iterator variable in Python. The closest approximation is a loop that uses an anonymous function as follows:

def loop(f, n):
    for i in xrange(n): f()

loop(lambda: <insert expression here>, 5)

However, this approach is slightly more intricate than using a standard for loop and isn't commonly used.

Another option is to employ the '_' variable, which effectively serves as an additional variable. However, it's important to note that '_' holds the result of the previous expression in an interactive Python session, making its usage in this context somewhat undesirable.

Furthermore, while '_' is a syntactically valid variable name, it can lead to potential conflicts. For instance:

for _ in xrange(10): pass

_ # The resulting value is 9

1+2 # The result is still 3, even though it should be 2 since '_' is set to 9

It is generally considered good practice to use explicit iterator variables in for loops to maintain code clarity and avoid potential issues.

The above is the detailed content of Can You Loop in Python Without an Explicit Iterator?. For more information, please follow other related articles on the PHP Chinese website!