How to replace a sting using python-CodePudding

I want to replace a string ('None') with NULL without quote.

For example:

data  = ('a','None','1','None')

And desired result:

result = "'a', NULL, '1', NULL"

Is there a way to get the expected result? Thanks in advance!!

CodePudding user response：

You can use join to build the resulting string:

data  = ('a','None','1','None')
t = ', '.join('NULL' if t == 'None' else repr(t) for t in data)

t is then the string "'a', NULL, '1', NULL".

But I really cannot imagine a real world use case for that...

CodePudding user response：

NULL is not a valid keyword in Python. Instead, you use None. In addition, you cannot modify a Tuple.

If you are using a list, however;

data[1] = None

CodePudding user response：

Use a generator comprehension along with the tuple() function:

data = ('a', 'None', '1', 'None')

# For NULL without quotes
result = tuple(el if el is not 'None' else NULL for el in data)

# 'NULL' with quotes
result = tuple(el if el is not 'None' else 'NULL' for el in data)

If you want your final result to be a comma-seperated string of values, use this:

# Replace 'NULL' with NULL if you want to reference the variable
new_result = ', '.join(el if el is not 'None' else 'NULL' for el in data)