fixed string to get rid of warning

goodman_pipeline/core/core.py

@@ -3267,7 +3267,7 @@ def trace_targets(ccd, target_list, sampling_step=5, pol_deg=2, nfwhm=5,
     return all_traces
 
 
-def validate_ccd_region(ccd_region, regexp='^\[\d*:\d*,\d*:\d*\]$'):
+def validate_ccd_region(ccd_region, regexp=r'^\[\d*:\d*,\d*:\d*\]$'):
     compiled_reg_exp = re.compile(regexp)
     if not compiled_reg_exp.match(ccd_region):
         raise SyntaxError("ccd regions must be defined in the format "