python将“ unicode”转换为列表

Question

I have a doubt about treat a return type in python.

I have a database function that returns this as value:

(1,13616,,"My string, that can have comma",170.90)

I put this into a variable and did test the type:

print(type(var))

I got the result:

<type 'unicode'>

I want to convert this to a list and get the values separeteds by comma.

Ex.:

var[0] = 1
var[1] = 13616
var[2] = None
var[3] = "My string, that can have comma"
var[4] = 170.90

Is it possible?

Answer 1

Using standard library csv readers:

>>> import csv
>>> s = u'(1,13616,,"My string, that can have comma",170.90)'
>>> [var] = csv.reader([s[1:-1]])
>>> var[3]
'My string, that can have comma'

Some caveats:

• var[2] will be an empty string, not None , but you can post-process that.
• numbers will be strings and also need post-processing, since csv does not tell the difference between 0 and '0' .

Answer 2

You can try to do the following:

b = []
for i in a:
    if i != None:
        b.append(i)
    if i == None:
        b.append(None)

print (type(b))

Answer 3

The issue is not with the comma.

this works fine:

a = (1,13616,"My string, that can have comma",170.90)

and this also works:

a = (1,13616,None,"My string, that can have comma",170.90)

but when you leave two commas ",," it doesn't work.

Answer 4

Unicode strings are (basically) just strings in Python2 (in Python3, remove the word "basically" in that last sentence). They're written as literals by prefixing a u before the string (compare raw-strings r"something" , or Py3.4+ formatter strings f"{some_var}thing" )

Just strip off your parens and split by comma. You'll have to do some post-parsing if you want 170.90 instead of u'170.90' or None instead of u'' , but I'll leave that for you to decide.

>>> var.strip(u'()').split(u',')
[u'1', u'13616', u'', u'"My string', u' that can have comma"', u'170.90']