1 | initial version |

Not offended at all! I didn't know about this myself until now.

This works:

```
sage: (x*y^3).factor_list()
[(x, 1), (y, 3)]
sage: mul([x, y, y, y])
x*y^3
```

And, if you want to go from the factor list to the expression:

```
sage: a = (x*y^3).factor_list()
sage: mul(map(lambda x: x[0]^x[1], a))
x*y^3
```

Hope this helps!

2 | No.2 Revision |

Not offended at all! I didn't know about this myself until now.

This works:

```
sage: (x*y^3).factor_list()
[(x, 1), (y, 3)]
sage: mul([x, y, y, y])
x*y^3
```

And, if you want to go from the factor list to the expression:

```
sage: a = (x*y^3).factor_list()
sage:
```~~mul(map(lambda x: x[0]^x[1], a))
~~mul(t^m for t, m in a)
x*y^3

Hope this helps!

Copyright Sage, 2010. Some rights reserved under creative commons license. Content on this site is licensed under a Creative Commons Attribution Share Alike 3.0 license.