Python has some conventions for variable names. You can use any letter, the special characters “_” and every number provided you do not start with it. White spaces and signs with special meanings in Python, as “+” and “-” are not allowed.
Python variable names are case-sensitive, so EcoRI and ecoRI are not the same variable.
>>> EcoRI = 'GAATTC' >>> ecoRI Traceback (most recent call last): File "<stdin>", line 1, in ? NameError: name 'ecoRI' is not defined >>> ecori Traceback (most recent call last): File "<stdin>", line 1, in ? NameError: name 'ecori' is not defined >>> EcoRI 'GAATTC'
Among the words you can construct with these letters, there are some reserved words for Python and can not be used as variable names. These keywords define the language rules and have special meanings in Python. Here is the list of all of them:
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