Online regex tester and debugger: PHP, PCRE, Python, Golang and JavaScript

Checking regex rules and see immediate result, with nice interface and explanations.

My regex with Python:

(?=[a-zA-Z_]+)\b[a-zA-Z1-9_]+\.

Look at the following example, my aim is to find the part “OC_2.” to remove it with re.sub(), but still leave “1.” because it belongs to a number:

OC_2.Ccold = 1.005 * OC_2.m_dot_air;

Source: Online regex tester and debugger: PHP, PCRE, Python, Golang and JavaScript