circuitpython/tests/io/file_with.py

f = open("data/file1")

with f as f2:
    print(f2.read())

# File should be closed
try:
    f.read()
except:
    # Note: CPython and us throw different exception trying to read from
    # close file.
    print("can't read file after with")


# Regression test: test that exception in with initialization properly
# thrown and doesn't crash.
try:
    with open("__non_existent", "r"):
        pass
except OSError:
    print("OSError")