Is there a Python function equivalent to Gamma[a, z] in Mathematica?

Question

I believe the incomplete Gamma function implemented in Mathematica is equivalent to an unregularized version of the upper gamma function.. The Gamma incomplete function as implemented in scipy is a regularized lower gamma function.. However, I may be wrong as my knowledge in this area is zero. I need to compute an equivalent of the incomplete gamma function from Mathematica in Python

Thank you in advance for all the help!

Answer 1

The scipy.special module contains an implementation of both the lower incomplete gamma function scipy.special.gammainc and the upper incomplete gamma function scipy.special.gammaincc (note the second c at the end)

scipy gives a scaled version of Mathematicas equivalent. If a>0 in Gamma[a, x] you should be able to use:

from scipy.special import gamma, gammaincc
gamma(0.01)*(gammaincc(0.01, 1))
# 0.22036593781812577

for the equivalent of Gamma[0.01, 1] in Mathematica.