Python’s standard library is very extensive, offering a wide range of facilities as indicated by the long table of contents listed below. The library contains built-in modules (written in C) that provide access to system functionality such as file I/O that would otherwise be inaccessible to Python programmers, as well as modules written in Python that provide standardized solutions for many problems that occur in everyday programming. Some of these modules are explicitly designed to encourage and enhance the portability of Python programs by abstracting away platform-specifics into platform-neutral APIs.
string¶for i in range(5):
for j in range(2):
print("this is ({},{}) integer".format(i,j))
this is (0,0) integer this is (0,1) integer this is (1,0) integer this is (1,1) integer this is (2,0) integer this is (2,1) integer this is (3,0) integer this is (3,1) integer this is (4,0) integer this is (4,1) integer
import re
s = 'Hello from shubhamg199630@gmail.com to priya@yahoo.com about\
the meeting @2PM. Can we meet today for an important decision?\
Based on previous meeting minute we had decided to write an emailto\
abc@example.com. In case we do not get reply.\
Hello from shubhamg@gmail.com to priya2@yahoo.com about\
the meeting @2PM. Can we meet today for an important decision?\
Based on previous meeting minute we had decided to write an emailto\
abcd@example.com. In case we do not get reply\
Hello from shubhamg19@gmail.com to priya5@yahoo.com about\
the meeting @2PM. Can we meet today for an important decision?\
Based on previous meeting minute we had decided to write an emailto\
abct@example.com. In case we do not get reply'
lst = re.findall('\S+@\S+', s)
print(lst)
['shubhamg199630@gmail.com', 'priya@yahoo.com', 'abc@example.com.', 'shubhamg@gmail.com', 'priya2@yahoo.com', 'abcd@example.com.', 'shubhamg19@gmail.com', 'priya5@yahoo.com', 'abct@example.com.']
collections¶from collections import namedtuple
point = namedtuple('Point', ['x', 'y'])
point(11,12)
Point(x=11, y=12)
point(2,3)
Point(x=2, y=3)
from collections import Counter
A = [ 1,3,5,6,8,6,5,4,5,6,5,4,3,2]
Counter(A)
Counter({1: 1, 3: 2, 5: 4, 6: 3, 8: 1, 4: 2, 2: 1})
itertools¶from itertools import permutations
L = ["a","b","c","d","e"]
for item in permutations(L,2):
print(item)
('a', 'b')
('a', 'c')
('a', 'd')
('b', 'a')
('b', 'c')
('b', 'd')
('c', 'a')
('c', 'b')
('c', 'd')
('d', 'a')
('d', 'b')
('d', 'c')
for item in permutations(L,3):
print(item)
('a', 'b', 'c')
('a', 'b', 'd')
('a', 'c', 'b')
('a', 'c', 'd')
('a', 'd', 'b')
('a', 'd', 'c')
('b', 'a', 'c')
('b', 'a', 'd')
('b', 'c', 'a')
('b', 'c', 'd')
('b', 'd', 'a')
('b', 'd', 'c')
('c', 'a', 'b')
('c', 'a', 'd')
('c', 'b', 'a')
('c', 'b', 'd')
('c', 'd', 'a')
('c', 'd', 'b')
('d', 'a', 'b')
('d', 'a', 'c')
('d', 'b', 'a')
('d', 'b', 'c')
('d', 'c', 'a')
('d', 'c', 'b')
os¶import os
path = "plot"
os.path.isdir(path)
True
path = "1. DataStructure.ipynb"
os.path.isfile(path)
True
os.listdir()
['.git', '.gitignore', '.ipynb_checkpoints', '1. DataStructure.ipynb', '1.1-MiniAssignment-DNAcount.ipynb', '2. LoopAndCondition.ipynb', '3. Input and Output.ipynb', '4. FunctionAndClass.ipynb', '5. Learning from Errors.ipynb', '6. The Python Standard Library.ipynb', 'data', 'Learning to read error.ipynb', 'plot', 'Project1-Fern-I.ipynb', 'Project2-Rwalk.ipynb', 'Project3-Ncharges.ipynb', 'Project4-Diffusion.ipynb', 'Project5-Fern-II.ipynb', 'README.md']
import os
# Running the aforementioned command and saving its output
output = os.popen('wmic process get description, processid').read()
# Displaying the output
print(output[0:1000])
Description ProcessId System Idle Process 0 System 4 Registry 96 smss.exe 416 csrss.exe 640 csrss.exe 744 wininit.exe 772 services.exe 820 lsass.exe 868 winlogon.exe 940 svchost.exe 392 svchost.exe 576 fontdrvhost.exe 592 fontdrvhost.exe 588 WUDFHost.exe 564 svchost.exe 1068 svchost.exe 1120 dwm.exe 1208 svchost.exe 1344 svchost.exe 1352 svchost.exe
glob¶import glob
glob.glob('*.ipynb')
['1. DataStructure.ipynb', '1.1-MiniAssignment-DNAcount.ipynb', '2. LoopAndCondition.ipynb', '3. Input and Output.ipynb', '4. FunctionAndClass.ipynb', '5. Learning from Errors.ipynb', '6. The Python Standard Library.ipynb', 'Learning to read error.ipynb', 'Project1-Fern-I.ipynb', 'Project2-Rwalk.ipynb', 'Project3-Ncharges.ipynb', 'Project4-Diffusion.ipynb', 'Project5-Fern-II.ipynb']
time¶import time
t1 = time.time()
for i in range(1000001):
if i==1000000:
print("done!")
t2 = time.time()
t2-t1
done!
0.09277701377868652
urllib¶ff = open('data/web.txt','w')
import urllib.request
import urllib.parse
params = urllib.parse.urlencode({'spam': 1, 'eggs': 2, 'bacon': 0})
url = "http://www.python.org"
with urllib.request.urlopen(url) as f:
ff.write(f.read().decode('utf-8'))
ff.close()
tqdm¶import time
from tqdm import tqdm
mylist = [i for i in range(100)]
for i in tqdm(mylist):
time.sleep(0.5)
100%|██████████| 100/100 [00:50<00:00, 1.99it/s]