Difference between revisions of "Python/scripts"
From Christoph's Personal Wiki
(→Selective printing) |
(→Miscellaneous) |
||
(2 intermediate revisions by the same user not shown) | |||
Line 76: | Line 76: | ||
>>> re.findall('..', list) | >>> re.findall('..', list) | ||
</pre> | </pre> | ||
+ | |||
+ | ==OS== | ||
+ | *List create a list of the files and directories in the current working directory (pwd): | ||
+ | files = filter(os.path.isfile, os.listdir('.')) | ||
+ | dirs = filter(os.path.isdir, os.listdir('.')) | ||
+ | |||
+ | ==Miscellaneous== | ||
+ | * Get the current world population estimate (from census.gov): | ||
+ | $ curl -s <nowiki>http://www.census.gov/popclock/data/population/world</nowiki> | python -c 'import json,sys;obj=json.load(sys.stdin);print obj["world"]["population"]' | ||
+ | |||
+ | * Generate a password hash (change 'password' and 'SALT' values): | ||
+ | $ python -c "import crypt, getpass, pwd; print crypt.crypt('password', '\$6\$SALT\$')" | ||
+ | |||
+ | * Generate a random password: | ||
+ | $ python -c 'import string,random;print "".join(random.SystemRandom().choice(string.ascii_letters + string.digits) for _ in range(16))' | ||
[[Category:Scripting languages]] | [[Category:Scripting languages]] |
Latest revision as of 22:24, 23 December 2015
This article will list a bunch of quick-and-dirty Python tips-and-tricks, examples, code, etc.
Contents
Generate a random set of characters
Note: Useful for creating random user passwords after a reset.
$ python -c 'import random; print "".join([random.choice("abcdefghijklmnopqrstuvwxyz0123456789\!@#$%^&*(-_=+)") for i in range(9)])'
Lambda functions
In stead of creating a new function of
f(x): return x + 1
You could use a lambda function inline, like so:
function_var = lambda x: x + 1 >>> print function_var(2) 3
Selective printing
- Print every 4th character of the English alphabet starting with the letter/character 'c':
>>> import string >>> string.ascii_letters 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ' >>> string.ascii_letters[0:26] 'abcdefghijklmnopqrstuvwxy'
alpha_lc = map(chr, range(97, 123)) alpha_lc = [chr(i) for i in xrange(ord('a'), ord('z')+1)] alpha_uc = map(chr, range(65, 91)) alpha_ns = 'abcdefghijklmnopqrstuvwxyz' alpha_sp = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'] >>> alpha_ns[2::4] # Method 1 'cgkosw' >>> [alpha_lc[i] for i in range(2, len(alpha_lc), 4)] # Method 2 ['c', 'g', 'k', 'o', 's', 'w'] >>> map(chr, range(97, 123))[2::4] # Method 3 (one-liner) ['c', 'g', 'k', 'o', 's', 'w']
Iterative printing
- Input:
data = [1,2,3,4,5,6]
- Methods:
for i,k in zip(data[0::2], data[1::2]): print str(i), '+', str(k), '=', str(i+k) # ~OR~ for i in range(0, len(l), 2): print str(l[i]), '+', str(l[i + 1]), '=', str(l[i] + l[i + 1])
- Output:
1 + 2 = 3 3 + 4 = 7 5 + 6 = 11
- Other
l = [1,2,3,4,5,6] >>> zip(l, l[1:]) [(1, 2), (2, 3), (3, 4), (4, 5), (5, 6)] >>> zip(l, l[1:])[::2] [(1, 2), (3, 4), (5, 6)] >>> [a+b for a,b in zip(l, l[1:])[::2]] [3, 7, 11] >>> ["%d + %d = %d" % (a, b, a+b) for a,b in zip(l, l[1:])[::2]] ['1 + 2 = 3', '3 + 4 = 7', '5 + 6 = 11'] >>> list = '1234567890' >>> n = 2 >>> [list[i:i+n] for i in range(0, len(list), n)] ['12', '34', '56', '78', '90'] # The following two accomplish the same thing: >>> map(''.join, zip(*[iter(list)]*2)) >>> re.findall('..', list)
OS
- List create a list of the files and directories in the current working directory (pwd):
files = filter(os.path.isfile, os.listdir('.')) dirs = filter(os.path.isdir, os.listdir('.'))
Miscellaneous
- Get the current world population estimate (from census.gov):
$ curl -s http://www.census.gov/popclock/data/population/world | python -c 'import json,sys;obj=json.load(sys.stdin);print obj["world"]["population"]'
- Generate a password hash (change 'password' and 'SALT' values):
$ python -c "import crypt, getpass, pwd; print crypt.crypt('password', '\$6\$SALT\$')"
- Generate a random password:
$ python -c 'import string,random;print "".join(random.SystemRandom().choice(string.ascii_letters + string.digits) for _ in range(16))'