Python Pocket Reference, Second Edition

Other Built-in Modules

This section documents a handful of additional built-in modules. See the Python Library Reference for details on all built-ins and the Vaults of Parnassus web site at http://www.vex.net/parnassus/ for third-party modules and tools.

The math Module

The math module exports C standard math library tools for use in Python. Table 1-24 lists this module’s exports; see the Python Library Reference for more details. Also see the cmath module for complex number tools and the NumPy system for advanced numeric work. frexp and modf return two-item tuples for a single argument.

Table 1-24. math module exports

pi	e	acos(x)	asin(x)
atan(x)	atan2(x,y)	ceil(x)	cos(x)
cosh(x)	exp(x)	fabs(x)	floor(x)
fmod(x,y)	frexp(x)	hypot(x,y)	ldexp(x,y)
log(x)	log10(x)	modf(x)	pow(x,y)
sin(x)	sinh(x)	sqrt(x)	tan(x)
tanh(x)

The time Module

Following is a partial list of time module exports. See the Python Library Reference for more details.

clock( )

Returns the current CPU time as a floating-point number expressed in seconds (CPU time for process so far). Useful for benchmarking and timing code sections.

ctime(secs)

Converts a time expressed in seconds since the epoch to a string representing local time (e.g., ctime(time( ))). As of 2.1, the argument is optional and defaults to the current time if omitted.

time( )

Returns a floating-point number representing UTC time in seconds since the epoch. On Unix, epoch is 1970.

sleep(secs)

Suspends the process’s execution for ...