Question

I have CSV files that contain numerous values that I want to reference. I wanted to parse them succinctly using eval. Here’s what I tried:

line = fileHandle.readline()
while line != "":
  if line != "\n":
    parameter = line.split(',')[0]
    value = line.split(',')[2].replace("\n", "")
    eval("%s = \"%s\"" % (parameter, value))
    print(parameter + " = " + eval(parameter)) # a quick test
  line = fileHandle.readline()

What I get is:

Traceback (innermost last):
  File "<string>", line 73, in ?
  File "<string>", line 70, in createJMSProviders
  File "<string>", line 49, in createJMSProviderFromFile
  File "<string>", line 1
    externalProviderURL="tibjmsnaming://..."
                       ^
SyntaxError: invalid syntax

I reads to me like it is not possible to eval("externalProviderURL=\"tibjmsnaming://...\""). What is wrong with this statement?

Answer 1

eval() is for evaluation Python expressions, and assignment (a = 1) is a statement.
You’ll want exec().

>>> exec("externalProviderURL=\"tibjmsnaming://...\"")
>>> externalProviderURL
'tibjmsnaming://...'

(FYI, to use eval() you’d have to do externalProviderURL=eval("\"tibjmsnaming://...\""), but it looks like your situation is more suited to exec).