Tuesday, November 5, 2013

Python quick bits

Just random Python quick bits to jar my memory

List

mylist=['item1','item2','3']
Index starts at 0
for myitem in mylist:
 code here
methods:
  • append()
  • pop()
  • extend() # append list of items ['item4','item5']
  • insert(position,"item6)remote("item2")

Dictionary

mydictionary={'tag1':'item1','tag2':'item2'}
Reference items by keys
for mykey in mydictionary.keys()
 code here

Object types in Python: int, dict, list, str
Testing for object type:
 isinstance(variable,type)
 var1='foo'
  isinstance(var1,str)

User input from the command line:
 import sys
 variable=raw_input("Enter user question here: ")

Length of list: len(list)

Strings

To work with strings: import string
mystring.split() # default delimeter is spaces with multiple spaces treated as one


for item in list:
  do something with item

for piece in string:
  do somethign with piece

Working with files

file1='/path/to/file'
with open(file1,'r') as afileobj:
  for line in afileobj:
    code
* 'r' is the file mode. Look for other modes here.