Errata

after example 8-2 , there is an unnumbered example using "futures"
@coroutine
def save_value(value, callback):
print "Saving {} to database".format(value)
db_response = yield save_result_to_db(result, callback) # 1
print "Response from database: {}".format(db_response)

if __name__ == "__main__":
eventloop.put(
partial(save_value, "Hello World")
)

There is a mismatch between the save_value definition and use, as in the definition it requires a callback parameter, but in the use it isn't supplied. As previous example used callbacks, I think the callback is left over from there.

Note from the Author or Editor:
Fixed in 2nd ed

The derivative was approximated to a sum instead of a subtraction.

Note from the Author or Editor:
Fixed in 2nd ed.

the upper part of the fraction is u(x+dx,t) + u(x+dx,t) + 2.u(x,t) where it should be u(x+dx,t)+u(x-dx,t)+2.u(x,t) ? The 2nd term should be u(x-dx,t) (note the sign - instead of +) ?
Regards,
Louis

Note from the Author or Editor:
Fixed in 2nd edition

In the Example 9-2 in the book, the pool uses calculate_pi:
nbr_in_unit_circles = pool.map(calculate_pi, nbr_trials_per_process)

However, the name of the def in Example 9-1 is estimate_nbr_points_in_quarter_circle.

So the code should be:
nbr_in_unit_circles = pool.map(estimate_nbr_points_in_quarter_circle, nbr_trials_per_process)

Note from the Author or Editor:
Will fix for 2nd ed

In example 9-2, the pool.map calls a function "calculate_pi". But in example 9-1 it's called estimate_nbr_points_in_quarter_circle.

Note from the Author or Editor:
Will fix for 2nd ed

The text says "example 9-28 shows the important steps taken to share this array". But the code to do that is in example 9-30.

Note from the Author or Editor:
Thank you! Fixed for the 2nd edition.