Python : .pyc Extension Error While Creating [closed]

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Closed 9 years ago.

This is a Python module which provides the facilities for the polynomial evaluator. It is really nothing more than a bunch of Python code (mostly function definitions) inside a file. The name of the module is the name of the file, plus the .py suffix. The module name is not given in the text of the file, so i can rename module by simply renaming the file.

After a module has been used, Python will create a file with the same name and the extension .pyc. This is the byte code for the module. Python creates or recreates these as needed, so i really don't need to do anything about them.

Problem is: Python does not create .pyc extension. Why?

# This module contains operations to manipulate polynomials.
#

# Need some string services, and some standard system services.
import string, sys

#
# Function to evaluate a polynomial at x.  The polynomial is given
# as a list of coefficients, from the greatest to the least.  It returns
# the value of the polynomial at x.
def eval(x, poly):
'''Evaluate at x the polynomial with coefficients given in poly.
The value p(x) is returned.'''

sum = 0
while 1:
    sum = sum + poly[0]     # Add the next coef.
    poly = poly[1:]         # Done with that one.
    if not poly: break      # If no more, done entirely.
    sum = sum * x           # Mult by x (each coef gets x right num times)

return sum


def read(prompt = '', file = sys.stdin):
'''Read a line of integers and return the list of integers.'''

# Read a line
if prompt: print prompt,
line = file.readline()
if not line: 
    raise EOFError, 'File ended on attempt to read polynomial.'
line = line[:-1]
if line == 'quit':
    raise EOFError, 'Input quit on attempt to read polynomial.'

# Go through each item on the line, converting each one and adding it
# to retval.
retval = [ ];
for str in string.split(line):
    retval.append(int(str))

return retval

#
# Create a string of the polynomial in sort-of-readable form.
def srep(p):
'''Print the coefficient list as a polynomial.'''

# Get the exponent of first coefficient, plus 1.
exp = len(p)

# Go through the coefs and turn them into terms.
retval = ''
while p:
    # Adjust exponent.  Done here so continue will run it.
    exp = exp - 1

    # Strip first coefficient
    coef = p[0]
    p = p[1:]

    # If zero, leave it out.
    if coef == 0: continue

    # If adding, need a + or -.
    if retval:
        if coef >= 0:
            retval = retval + ' + '
        else:
            coef = -coef
            retval = retval + ' - '

    # Add the coefficient, if needed.
    if coef != 1 or exp == 0:
        retval = retval + str(coef)
        if exp != 0: retval = retval + '*'

    # Put the x, if we need it.
    if exp != 0:
        retval = retval + 'x'
        if exp != 1: retval = retval + '^' + str(exp)

# For zero, say that.
if not retval: retval = '0'

return retval

Answer 1

See here:

When a script is run by giving its name on the command line, the bytecode for the script is never written to a ".pyc" or ".pyo" file. Thus, the startup time of a script may be reduced by moving most of its code to a module and having a small bootstrap script that imports that module.

Thus, if you want to create a .pyc file, you have to import the script, not just run it from the command line. For example, you could do

python -c "import myscript"

instead of doing

python myscript.py