for

Python‎ > ‎Control Flow‎ > ‎

Definition
The for statement in Python returns the string or list in the numeric as it is argued.

Syntax
for "variable_name" "in" function ":"
argument

"else :"
argument

Parameters
wide range of parameters are permissible.

Examples

The for loop returns with::

import itertools
tuple=(3, 4, 1, 2)
z=itertools.islice(tuple,3)
for value in z: print(value)

>>>
3
4
1
>>>

for loop(itertools(lambda,list())

The return is:

from itertools import *
list = [("Python", "Lake"), ("Adil", "Waseem")]
for i in starmap(lambda x,y:(x, y, x+y), list):
print( i)

>>>
('Python', 'Lake', 'PythonLake')
('Adil', 'Waseem', 'AdilWaseem')
>>>

for loop in range(Decimal, int)

The method computed the int(value) of the decimal and then run loop through range() function.

from decimal import Decimal

a=int(Decimal(1.1).log10()+Decimal(1.233).logb()- Decimal(1.1).log10()%Decimal(.49).sqrt())

for i in range(a,10):

print(i)

print(i/Decimal(1.1).log10())

>>>

0
0E+29
1
24.15885792809678504023429545
2
48.31771585619357008046859090
3
72.47657378429035512070288634
4
96.63543171238714016093718179
5
120.7942896404839252011714772
6
144.9531475685807102414057727
7
169.1120054966774952816400681
8
193.2708634247742803218743636
9
217.4297213528710653621086590
>>>

for loop in itertools.accumulate(set.difference)

The returns with accumulate of items of difference between sets.

from decimal import Decimal
import itertools
set1={Decimal(0.1).to_integral_value(),Decimal(1.9).to_integral_exact(),Decimal(1.5000001).to_integral(), Decimal(10).shift(2)}
set2={Decimal(1).scaleb(0), Decimal(1).remainder_near(2),Decimal(1.0000).normalize()}

x=set1.difference(set2)

y=itertools.accumulate(x)
for value in y:
print(value)

>>>
1000
1000
1002
>>>

Here, this examples, mydb.db database is created and in that database Table3 is created with Fields, name, email, telephone and income. The values are displayed through for loop by order of income in html file.

Steps for creating virtual environment, startproject, startapp, creating database, and migrating the data, and running server to check the app.

virtualenenv pythonlake
cd pythonlake
.\Scripts\activate
pip install django
python .\Scripts\django-admin.py startproject mysite
python manage.py migrate
python manage.py startapp mydb
python manage.py makemigrations mydb

mysite/settings.py

INSTALLED_APPS = (

'django.contrib.admin',

'django.contrib.auth',

'django.contrib.contenttypes',

'django.contrib.sessions',

'django.contrib.messages',

'django.contrib.staticfiles','mydb',

)

mysite/urls.py

from django.conf.urls import url

from mydb.views import DataBase

urlpatterns = [

url(r'^$', DataBase),

]

mydb/views.py

from django.shortcuts import render

import sqlite3

def DataBase (request):

conn=sqlite3.connect('mydb.db')

cursor=conn.cursor()

cursor.execute('''CREATE TABLE table3(name text, phone text, email text, income text)''')

cursor.execute('''INSERT INTO table3 VALUES(' Erica ', ' 571 402 2992 ', ' erica.steve@ibm.com ', ' 180000 ')''')

cursor.execute('''INSERT INTO table3 VALUES(' Strube ', ' 571 402 2212 ', ' marya_strube@care.com ', ' 890000 ')''')

conn.commit()

for row in cursor.execute('SELECT * FROM table3 ORDER BY income'):

response=row

return render(request, 'mydb\index.html', {'response':response} )

mydb/index.html

<!DOCTYPE html>

<html>

<title>Table3</title>

</head>

<body>

</body>

</html>

The pyramid.response return with Response after getting string value from the for loop.

from wsgiref.simple_server import make_server
from pyramid.config import Configurator
from pyramid.response import Response

def hello_world(request):
response=Response()
for link in range(1,100):
response.text="Hi there. "*link
return response

if __name__ == '__main__':
config = Configurator()
config.add_route('hello', '/')
config.add_view(hello_world, route_name='hello')
app = config.make_wsgi_app()
server = make_server('0.0.0.0', 6500, app)
server.serve_forever()

The for loop returns the headers values.

>>> import requests

>>> r=requests.get('http://www.pythonlake.com/aboutus')

>>> for s in r.headers:

... print(s)

...

x-xss-protection

transfer-encoding

x-content-type-options

vary

expires

content-type

server

date

cache-control

accept-ranges

last-modified

x-robots-tag

alternate-protocol

The turtle graphics is created through the math functions.

import turtle

import random

import math

turtle.screensize(300,300)

turtle.speed(100)

turtle.pensize(1)

turtle.bgcolor("black")

color_list= ['snow', 'ghostwhite', 'whitesmoke', 'gainsboro', 'floralwhite', 'oldlace',

'linen', 'antiquewhite', 'papayawhip', 'blanchedalmond', 'bisque', 'peachpuff',

'navajowhite', 'lemonchiffon', 'mintcream', 'azure', 'aliceblue', 'lavender',

'lavenderblush', 'mistyrose', 'darkslategray', 'dimgray', 'slategray',

'lightslategray', 'gray', 'lightgrey', 'midnightblue', 'navy', 'cornflowerblue', 'darkslateblue',

'slateblue', 'mediumslateblue', 'lightslateblue', 'mediumblue', 'royalblue', 'blue',

'dodgerblue', 'deepskyblue', 'skyblue', 'lightskyblue', 'steelblue', 'lightsteelblue',

'lightblue', 'powderblue', 'paleturquoise', 'darkturquoise', 'mediumturquoise', 'turquoise',

'cyan', 'lightcyan', 'cadetblue', 'mediumaquamarine', 'aquamarine', 'darkgreen', 'darkolivegreen',

'darkseagreen', 'seagreen', 'mediumseagreen', 'lightseagreen', 'palegreen', 'springgreen',

'lawngreen', 'mediumspringgreen', 'greenyellow', 'limegreen', 'yellowgreen',

'forestgreen', 'olivedrab', 'darkkhaki', 'khaki', 'palegoldenrod', 'lightgoldenrodyellow',

'lightyellow', 'yellow', 'gold', 'lightgoldenrod', 'goldenrod', 'darkgoldenrod', 'rosybrown',

'indianred', 'saddlebrown', 'sandybrown',

'darksalmon', 'salmon', 'lightsalmon', 'orange', 'darkorange',

'coral', 'lightcoral', 'tomato', 'orangered', 'red', 'hotpink', 'deeppink', 'pink', 'lightpink',

'palevioletred', 'maroon', 'mediumvioletred', 'violetred',

'mediumorchid', 'darkorchid', 'darkviolet', 'blueviolet', 'purple', 'mediumpurple',

'thistle', 'snow2', 'snow3',

'snow4', 'seashell2', 'seashell3', 'seashell4', 'AntiqueWhite1', 'AntiqueWhite2',

'AntiqueWhite3', 'AntiqueWhite4', 'bisque2', 'bisque3', 'bisque4', 'PeachPuff2',

'PeachPuff3', 'PeachPuff4', 'NavajoWhite2', 'NavajoWhite3', 'NavajoWhite4',

'LemonChiffon2', 'LemonChiffon3', 'LemonChiffon4', 'cornsilk2', 'cornsilk3',

'cornsilk4', 'ivory2', 'ivory3', 'ivory4', 'honeydew2', 'honeydew3', 'honeydew4',

'LavenderBlush2', 'LavenderBlush3', 'LavenderBlush4', 'MistyRose2', 'MistyRose3',

'MistyRose4', 'azure2', 'azure3', 'azure4', 'SlateBlue1', 'SlateBlue2', 'SlateBlue3',

'SlateBlue4', 'RoyalBlue1', 'RoyalBlue2', 'RoyalBlue3', 'RoyalBlue4', 'blue2', 'blue4',

'DodgerBlue2', 'DodgerBlue3', 'DodgerBlue4', 'SteelBlue1', 'SteelBlue2',

'SteelBlue3', 'SteelBlue4', 'DeepSkyBlue2', 'DeepSkyBlue3', 'DeepSkyBlue4',

'SkyBlue1', 'SkyBlue2', 'SkyBlue3', 'SkyBlue4', 'LightSkyBlue1', 'LightSkyBlue2',

'LightSkyBlue3', 'LightSkyBlue4', 'SlateGray1', 'SlateGray2', 'SlateGray3',

'SlateGray4', 'LightSteelBlue1', 'LightSteelBlue2', 'LightSteelBlue3',

'LightSteelBlue4', 'LightBlue1', 'LightBlue2', 'LightBlue3', 'LightBlue4',

'LightCyan2', 'LightCyan3', 'LightCyan4', 'PaleTurquoise1', 'PaleTurquoise2',

'PaleTurquoise3', 'PaleTurquoise4', 'CadetBlue1', 'CadetBlue2', 'CadetBlue3',

'CadetBlue4', 'turquoise1', 'turquoise2', 'turquoise3', 'turquoise4', 'cyan2', 'cyan3',

'cyan4', 'DarkSlateGray1', 'DarkSlateGray2', 'DarkSlateGray3', 'DarkSlateGray4',

'aquamarine2', 'aquamarine4', 'DarkSeaGreen1', 'DarkSeaGreen2', 'DarkSeaGreen3',

'DarkSeaGreen4', 'SeaGreen1', 'SeaGreen2', 'SeaGreen3', 'PaleGreen1', 'PaleGreen2',

'PaleGreen3', 'PaleGreen4', 'SpringGreen2', 'SpringGreen3', 'SpringGreen4',

'green2', 'green3', 'green4', 'chartreuse2', 'chartreuse3', 'chartreuse4',

'OliveDrab1', 'OliveDrab2', 'OliveDrab4', 'DarkOliveGreen1', 'DarkOliveGreen2',

'DarkOliveGreen3', 'DarkOliveGreen4', 'khaki1', 'khaki2', 'khaki3', 'khaki4',

'LightGoldenrod1', 'LightGoldenrod2', 'LightGoldenrod3', 'LightGoldenrod4',

'LightYellow2', 'LightYellow3', 'LightYellow4', 'yellow2', 'yellow3', 'yellow4',

'gold2', 'gold3', 'gold4', 'goldenrod1', 'goldenrod2', 'goldenrod3', 'goldenrod4',

'DarkGoldenrod1', 'DarkGoldenrod2', 'DarkGoldenrod3', 'DarkGoldenrod4',

'RosyBrown1', 'RosyBrown2', 'RosyBrown3', 'RosyBrown4', 'IndianRed1', 'IndianRed2',

'IndianRed3', 'IndianRed4', 'sienna1', 'sienna2', 'sienna3', 'sienna4', 'burlywood1',

'burlywood2', 'burlywood3', 'burlywood4', 'wheat1', 'wheat2', 'wheat3', 'wheat4', 'tan1',

'tan2', 'tan4', 'chocolate1', 'chocolate2', 'chocolate3', 'firebrick1', 'firebrick2',

'firebrick3', 'firebrick4', 'brown1', 'brown2', 'brown3', 'brown4', 'salmon1', 'salmon2',

'salmon3', 'salmon4', 'LightSalmon2', 'LightSalmon3', 'LightSalmon4', 'orange2',

'orange3', 'orange4', 'DarkOrange1', 'DarkOrange2', 'DarkOrange3', 'DarkOrange4',

'coral1', 'coral2', 'coral3', 'coral4', 'tomato2', 'tomato3', 'tomato4', 'OrangeRed2',

'OrangeRed3', 'OrangeRed4', 'red2', 'red3', 'red4', 'DeepPink2', 'DeepPink3', 'DeepPink4',

'HotPink1', 'HotPink2', 'HotPink3', 'HotPink4', 'pink1', 'pink2', 'pink3', 'pink4',

'LightPink1', 'LightPink2', 'LightPink3', 'LightPink4', 'PaleVioletRed1',

'PaleVioletRed2', 'PaleVioletRed3', 'PaleVioletRed4', 'maroon1', 'maroon2',

'maroon3', 'maroon4', 'VioletRed1', 'VioletRed2', 'VioletRed3', 'VioletRed4',

'magenta2', 'magenta3', 'magenta4', 'orchid1', 'orchid2', 'orchid3', 'orchid4', 'plum1',

'plum2', 'plum3', 'plum4', 'MediumOrchid1', 'MediumOrchid2', 'MediumOrchid3',

'MediumOrchid4', 'DarkOrchid1', 'DarkOrchid2', 'DarkOrchid3', 'DarkOrchid4',

'purple1', 'purple2', 'purple3', 'purple4', 'MediumPurple1', 'MediumPurple2',

'MediumPurple3', 'MediumPurple4', 'thistle1', 'thistle2', 'thistle3', 'thistle4',

'gray1', 'gray2', 'gray3', 'gray4', 'gray5', 'gray6', 'gray7', 'gray8', 'gray9', 'gray10',

'gray11', 'gray12', 'gray13', 'gray14', 'gray15', 'gray16', 'gray17', 'gray18', 'gray19',

'gray20', 'gray21', 'gray22', 'gray23', 'gray24', 'gray25', 'gray26', 'gray27', 'gray28',

'gray29', 'gray30', 'gray31', 'gray32', 'gray33', 'gray34', 'gray35', 'gray36', 'gray37',

'gray38', 'gray39', 'gray40', 'gray42', 'gray43', 'gray44', 'gray45', 'gray46', 'gray47',

'gray48', 'gray49', 'gray50', 'gray51', 'gray52', 'gray53', 'gray54', 'gray55', 'gray56',

'gray57', 'gray58', 'gray59', 'gray60', 'gray61', 'gray62', 'gray63', 'gray64', 'gray65',

'gray66', 'gray67', 'gray68', 'gray69', 'gray70', 'gray71', 'gray72', 'gray73', 'gray74',

'gray75', 'gray76', 'gray77', 'gray78', 'gray79', 'gray80', 'gray81', 'gray82', 'gray83',

'gray84', 'gray85', 'gray86', 'gray87', 'gray88', 'gray89', 'gray90', 'gray91', 'gray92',

'gray93', 'gray94', 'gray95', 'gray97', 'gray98', 'gray99']

for i in range(1,400):

colors=random.sample(color_list,1)

p=math.sin(i)

q=math.cos(i)

s=random.randrange(1,3)

tuple=(turtle.setpos(p,q), turtle.pd(), turtle.color(colors),

turtle.dot(10+i/50),turtle.rt(i), turtle.forward(20+i),turtle.pensize(s))

turtle.hideturtle()

The turtle graphics is generated through the turtle.stamp().

import turtle

import random

turtle.screensize(200,200)