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Boston Python Workshop 3/Data types: Difference between revisions
→Strings are a lot like lists
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==Strings==
* Strings are bits of text, and contain characters like numbers, letters, whitespace, and punctuation.
* String are surrounded by quotes.
* Use triple-quotes (""") to create whitespace-preserving multi-line strings.
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>>> "Hello"
'Hello'
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====String concatenation====
<pre>
>>> "Hello" + "World"
HelloWorld
>>> "Hello" + "World" + 1
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: cannot concatenate 'str' and 'int' objects
>>> "Hello" + "World" + str(1)
'HelloWorld1'
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====Printing strings====
<pre>
HelloWorld
>>> print "Hello", "World"
Hello World
Hello World 1
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was US $1.4 million.
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====Types====
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<type 'str'>
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▲<b>Printing strings with '+'</b>: print "Hello" + "World"<br />
▲<b>Printing strings with ','</b>: print "Hello", "World", 1<br />
==Booleans==
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* Use lists to store data where order matters.
* Lists are indexed starting with 0.
====List initialization====
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>>> my_string
'Hello Jessica'
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* One big way in which strings are different from lists is that lists are mutable (you can change them), and strings are immutable (you can't change them). To "change" a string you have to make a copy:
<pre>
>>> h = "Hello"
>>> h[0] = "J"
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: 'str' object does not support item assignment
>>> h = "J" + h[1:]
>>> h
'Jello'
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