Difference between revisions of "Python"
From neil.tappsville.com
Jump to navigationJump to search (Created page with " ==== Python version of a perl hash ==== <pre> import collections ; def tree() : return collections.defaultdict(tree) hash = tree() hash'outer_key''inner key' = "v...") |
m |
||
| (6 intermediate revisions by the same user not shown) | |||
| Line 1: | Line 1: | ||
| + | ==== Data Types ==== | ||
| + | <pre> | ||
| + | int 1234 | ||
| + | >>> type(1234) | ||
| + | <class 'int'> | ||
| + | float 55.50 | ||
| + | >>> type(55.50) | ||
| + | <class 'float'> | ||
| + | complex | ||
| + | >>> type(6+4j) | ||
| + | <class 'complex'> | ||
| + | string hellow | ||
| + | >>> type("hello") | ||
| + | <class 'str'> | ||
| + | Square list [1,2,3,4] | ||
| + | >>> type([1,2,3,4]) | ||
| + | <class 'list'> | ||
| + | Round tuple (1,2,3,4) | ||
| + | >>> type((1,2,3,4)) | ||
| + | <class 'tuple'> | ||
| + | Curly dict {1:"one", 2:"two", 3:"three"} | ||
| + | >>> type({1:"one", 2:"two", 3:"three"}) | ||
| + | <class 'dict'> | ||
| + | </pre> | ||
| + | |||
==== Python version of a perl hash ==== | ==== Python version of a perl hash ==== | ||
| Line 15: | Line 40: | ||
; else : print "Hash has some data" | ; else : print "Hash has some data" | ||
</pre> | </pre> | ||
| + | |||
| + | === Strings === | ||
| + | |||
| + | * Use <code>"'{0}' is longer than '{1}'".format(name1, name2)</code> | ||
| + | |||
| + | * The new-style {} formatting uses {} codes and the .format method | ||
| + | * <code>'It will cost ${0} dollars.'.format(95)</code> | ||
| + | * The old-style % formatting uses % codes for formatting: | ||
| + | * <code>'It will cost $%d dollars.' % 95</code> | ||
| + | * Note that with old-style formatting, you have to specify multiple arguments using a tuple: | ||
| + | * <code>'%d days and %d nights' % (40, 40)</code> | ||
| + | |||
| + | The 'new' / safe way to concatenate strings in a print statement | ||
| + | print("%s is %d years old." % (name, age)) | ||
| + | |||
| + | ===XML=== | ||
| + | |||
| + | https://www.datacamp.com/community/tutorials/python-xml-elementtree | ||
| + | |||
| + | |||
| + | == Update Modules== | ||
| + | |||
| + | sudo python3 -m pip list --outdated --format=freeze | grep -v '^\-e' | cut -d = -f 1 | xargs -n1 sudo python3 -m pip install -U | ||
Latest revision as of 06:14, 1 June 2020
Data Types
int 1234
>>> type(1234)
<class 'int'>
float 55.50
>>> type(55.50)
<class 'float'>
complex
>>> type(6+4j)
<class 'complex'>
string hellow
>>> type("hello")
<class 'str'>
Square list [1,2,3,4]
>>> type([1,2,3,4])
<class 'list'>
Round tuple (1,2,3,4)
>>> type((1,2,3,4))
<class 'tuple'>
Curly dict {1:"one", 2:"two", 3:"three"}
>>> type({1:"one", 2:"two", 3:"three"})
<class 'dict'>
Python version of a perl hash
import collections ; def tree() : return collections.defaultdict(tree) hash = tree() hash[['outer_key']][['inner key']] = "value" ; if not bool(hash) : print "Hash is empty" ; else : print "Hash has some data"
Strings
- Use
"'{0}' is longer than '{1}'".format(name1, name2)
- The new-style {} formatting uses {} codes and the .format method
'It will cost ${0} dollars.'.format(95)- The old-style % formatting uses % codes for formatting:
'It will cost $%d dollars.' % 95- Note that with old-style formatting, you have to specify multiple arguments using a tuple:
'%d days and %d nights' % (40, 40)
The 'new' / safe way to concatenate strings in a print statement
print("%s is %d years old." % (name, age))
XML
https://www.datacamp.com/community/tutorials/python-xml-elementtree
Update Modules
sudo python3 -m pip list --outdated --format=freeze | grep -v '^\-e' | cut -d = -f 1 | xargs -n1 sudo python3 -m pip install -U
