When I print out a value it has a u in front of it, I think it is some type notation, what is it? Where I can find a list of such notations?
It meant UNICODE string literal before Python 3.
Documentation about all these literal adornments can be found there.
Unicode Constructors talks about unicode.
That's creating a unicode string. I'd recommend this section from Dive into Python on the topic
There are many advantages to explicitly using unicode, the most common reason for doing so is to force integrity when working with a database.
Related
Like in:
u'Hello'
My guess is that it indicates "Unicode", is that correct?
If so, since when has it been available?
You're right, see 3.1.3. Unicode Strings.
It's been the syntax since Python 2.0.
Python 3 made them redundant, as the default string type is Unicode. Versions 3.0 through 3.2 removed them, but they were re-added in 3.3+ for compatibility with Python 2 to aide the 2 to 3 transition.
The u in u'Some String' means that your string is a Unicode string.
Q: I'm in a terrible, awful hurry and I landed here from Google Search. I'm trying to write this data to a file, I'm getting an error, and I need the dead simplest, probably flawed, solution this second.
A: You should really read Joel's Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!) essay on character sets.
Q: sry no time code pls
A: Fine. try str('Some String') or 'Some String'.encode('ascii', 'ignore'). But you should really read some of the answers and discussion on Converting a Unicode string and this excellent, excellent, primer on character encoding.
My guess is that it indicates "Unicode", is it correct?
Yes.
If so, since when is it available?
Python 2.x.
In Python 3.x the strings use Unicode by default and there's no need for the u prefix. Note: in Python 3.0-3.2, the u is a syntax error. In Python 3.3+ it's legal again to make it easier to write 2/3 compatible apps.
I came here because I had funny-char-syndrome on my requests output. I thought response.text would give me a properly decoded string, but in the output I found funny double-chars where German umlauts should have been.
Turns out response.encoding was empty somehow and so response did not know how to properly decode the content and just treated it as ASCII (I guess).
My solution was to get the raw bytes with 'response.content' and manually apply decode('utf_8') to it. The result was schöne Umlaute.
The correctly decoded
für
vs. the improperly decoded
fĂźr
All strings meant for humans should use u"".
I found that the following mindset helps a lot when dealing with Python strings: All Python manifest strings should use the u"" syntax. The "" syntax is for byte arrays, only.
Before the bashing begins, let me explain. Most Python programs start out with using "" for strings. But then they need to support documentation off the Internet, so they start using "".decode and all of a sudden they are getting exceptions everywhere about decoding this and that - all because of the use of "" for strings. In this case, Unicode does act like a virus and will wreak havoc.
But, if you follow my rule, you won't have this infection (because you will already be infected).
Like in:
u'Hello'
My guess is that it indicates "Unicode", is that correct?
If so, since when has it been available?
You're right, see 3.1.3. Unicode Strings.
It's been the syntax since Python 2.0.
Python 3 made them redundant, as the default string type is Unicode. Versions 3.0 through 3.2 removed them, but they were re-added in 3.3+ for compatibility with Python 2 to aide the 2 to 3 transition.
The u in u'Some String' means that your string is a Unicode string.
Q: I'm in a terrible, awful hurry and I landed here from Google Search. I'm trying to write this data to a file, I'm getting an error, and I need the dead simplest, probably flawed, solution this second.
A: You should really read Joel's Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!) essay on character sets.
Q: sry no time code pls
A: Fine. try str('Some String') or 'Some String'.encode('ascii', 'ignore'). But you should really read some of the answers and discussion on Converting a Unicode string and this excellent, excellent, primer on character encoding.
My guess is that it indicates "Unicode", is it correct?
Yes.
If so, since when is it available?
Python 2.x.
In Python 3.x the strings use Unicode by default and there's no need for the u prefix. Note: in Python 3.0-3.2, the u is a syntax error. In Python 3.3+ it's legal again to make it easier to write 2/3 compatible apps.
I came here because I had funny-char-syndrome on my requests output. I thought response.text would give me a properly decoded string, but in the output I found funny double-chars where German umlauts should have been.
Turns out response.encoding was empty somehow and so response did not know how to properly decode the content and just treated it as ASCII (I guess).
My solution was to get the raw bytes with 'response.content' and manually apply decode('utf_8') to it. The result was schöne Umlaute.
The correctly decoded
für
vs. the improperly decoded
fĂźr
All strings meant for humans should use u"".
I found that the following mindset helps a lot when dealing with Python strings: All Python manifest strings should use the u"" syntax. The "" syntax is for byte arrays, only.
Before the bashing begins, let me explain. Most Python programs start out with using "" for strings. But then they need to support documentation off the Internet, so they start using "".decode and all of a sudden they are getting exceptions everywhere about decoding this and that - all because of the use of "" for strings. In this case, Unicode does act like a virus and will wreak havoc.
But, if you follow my rule, you won't have this infection (because you will already be infected).
Like in:
u'Hello'
My guess is that it indicates "Unicode", is that correct?
If so, since when has it been available?
You're right, see 3.1.3. Unicode Strings.
It's been the syntax since Python 2.0.
Python 3 made them redundant, as the default string type is Unicode. Versions 3.0 through 3.2 removed them, but they were re-added in 3.3+ for compatibility with Python 2 to aide the 2 to 3 transition.
The u in u'Some String' means that your string is a Unicode string.
Q: I'm in a terrible, awful hurry and I landed here from Google Search. I'm trying to write this data to a file, I'm getting an error, and I need the dead simplest, probably flawed, solution this second.
A: You should really read Joel's Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!) essay on character sets.
Q: sry no time code pls
A: Fine. try str('Some String') or 'Some String'.encode('ascii', 'ignore'). But you should really read some of the answers and discussion on Converting a Unicode string and this excellent, excellent, primer on character encoding.
My guess is that it indicates "Unicode", is it correct?
Yes.
If so, since when is it available?
Python 2.x.
In Python 3.x the strings use Unicode by default and there's no need for the u prefix. Note: in Python 3.0-3.2, the u is a syntax error. In Python 3.3+ it's legal again to make it easier to write 2/3 compatible apps.
I came here because I had funny-char-syndrome on my requests output. I thought response.text would give me a properly decoded string, but in the output I found funny double-chars where German umlauts should have been.
Turns out response.encoding was empty somehow and so response did not know how to properly decode the content and just treated it as ASCII (I guess).
My solution was to get the raw bytes with 'response.content' and manually apply decode('utf_8') to it. The result was schöne Umlaute.
The correctly decoded
für
vs. the improperly decoded
fĂźr
All strings meant for humans should use u"".
I found that the following mindset helps a lot when dealing with Python strings: All Python manifest strings should use the u"" syntax. The "" syntax is for byte arrays, only.
Before the bashing begins, let me explain. Most Python programs start out with using "" for strings. But then they need to support documentation off the Internet, so they start using "".decode and all of a sudden they are getting exceptions everywhere about decoding this and that - all because of the use of "" for strings. In this case, Unicode does act like a virus and will wreak havoc.
But, if you follow my rule, you won't have this infection (because you will already be infected).
Many problems I've ran into in Python have been related to not having something in Unicode. Is there any good reason to not use Unicode by default? I understand needing to translate something in ASCII, but it seems to be the exception and not the rule.
I know Python 3 uses Unicode for all strings. Should this encourage me as a developer to unicode() all my strings?
Generally, I'm going to say "no" there's not a good reason to use string over unicode. Remember, as well, that you don't have to call unicode() to create a unicode string, you can do so by prefixing the string with a lowercase u like u"this is a unicode string".
In Python 2.x:
A str object is basically just a sequence of bytes.
A unicode object is a sequence of characters.
Knowing this, it should be easy to choose the correct type:
If you want a string of characters use unicode.
If you want an string encoded as bytes use str (in many other languages you'd use byte[] here).
In Python 3.x the type str is a string of characters, just as you would expect. You can use bytes if you want a sequence of bytes.
Like in:
u'Hello'
My guess is that it indicates "Unicode", is that correct?
If so, since when has it been available?
You're right, see 3.1.3. Unicode Strings.
It's been the syntax since Python 2.0.
Python 3 made them redundant, as the default string type is Unicode. Versions 3.0 through 3.2 removed them, but they were re-added in 3.3+ for compatibility with Python 2 to aide the 2 to 3 transition.
The u in u'Some String' means that your string is a Unicode string.
Q: I'm in a terrible, awful hurry and I landed here from Google Search. I'm trying to write this data to a file, I'm getting an error, and I need the dead simplest, probably flawed, solution this second.
A: You should really read Joel's Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!) essay on character sets.
Q: sry no time code pls
A: Fine. try str('Some String') or 'Some String'.encode('ascii', 'ignore'). But you should really read some of the answers and discussion on Converting a Unicode string and this excellent, excellent, primer on character encoding.
My guess is that it indicates "Unicode", is it correct?
Yes.
If so, since when is it available?
Python 2.x.
In Python 3.x the strings use Unicode by default and there's no need for the u prefix. Note: in Python 3.0-3.2, the u is a syntax error. In Python 3.3+ it's legal again to make it easier to write 2/3 compatible apps.
I came here because I had funny-char-syndrome on my requests output. I thought response.text would give me a properly decoded string, but in the output I found funny double-chars where German umlauts should have been.
Turns out response.encoding was empty somehow and so response did not know how to properly decode the content and just treated it as ASCII (I guess).
My solution was to get the raw bytes with 'response.content' and manually apply decode('utf_8') to it. The result was schöne Umlaute.
The correctly decoded
für
vs. the improperly decoded
fĂźr
All strings meant for humans should use u"".
I found that the following mindset helps a lot when dealing with Python strings: All Python manifest strings should use the u"" syntax. The "" syntax is for byte arrays, only.
Before the bashing begins, let me explain. Most Python programs start out with using "" for strings. But then they need to support documentation off the Internet, so they start using "".decode and all of a sudden they are getting exceptions everywhere about decoding this and that - all because of the use of "" for strings. In this case, Unicode does act like a virus and will wreak havoc.
But, if you follow my rule, you won't have this infection (because you will already be infected).