How do you compare dictionaries in Python for equality?

Understanding Equality Comparison between Dictionaries

In Python, comparing two dictionaries can be tricky. One straightforward approach is to iterate through their key, value pairs and check for equality. Here's an example:

<code class="python">x = dict(a=1, b=2)
y = dict(a=2, b=2)

for x_values, y_values in zip(x.items(), y.items()):
    if x_values == y_values:
        print('Ok', x_values, y_values)
    else:
        print('Not', x_values, y_values)</code>

While this code works, it's not particularly elegant. A more concise option is to use a dictionary comprehension:

<code class="python">shared_items = {k: x[k] for k in x if k in y and x[k] == y[k]}</code>

This comprehension creates a new dictionary (shared_items) containing only the keys and values that are shared between x and y. By calculating the length of this dictionary, we can determine the number of equal key, value pairs:

<code class="python">print(len(shared_items))</code>

The above is the detailed content of How do you compare dictionaries in Python for equality?. For more information, please follow other related articles on the PHP Chinese website!