1
00:00:00,000 --> 00:00:00,800
[no audio]

2
00:00:00,800 --> 00:00:02,100
Friends, here we are going to

3
00:00:02,100 --> 00:00:04,800
see how to you use functions of one Python

4
00:00:04,800 --> 00:00:08,000
Script into another Python Script, and what is

5
00:00:08,000 --> 00:00:10,000
'__', name variable,

6
00:00:11,100 --> 00:00:15,100
and finally we are going to see how to create user-defined modules.

7
00:00:16,300 --> 00:00:19,400
First, let me start with a simple Python Script.

8
00:00:19,400 --> 00:00:21,400
[no audio]

9
00:00:21,400 --> 00:00:25,200
Let me create a simple Python Script called 'script1.py'.

10
00:00:26,400 --> 00:00:29,900
Now here I am going to define two functions, one is for addition.

11
00:00:29,900 --> 00:00:32,200
[no audio]

12
00:00:32,299 --> 00:00:33,800
Now let me 'print("

13
00:00:35,300 --> 00:00:36,300
The addition of

14
00:00:39,300 --> 00:00:45,400
and is", simply 'a + b'.

15
00:00:45,400 --> 00:00:48,200
[no audio]

16
00:00:48,200 --> 00:00:49,800
Then let me write

17
00:00:49,800 --> 00:00:51,200
'return None'.

18
00:00:52,700 --> 00:00:56,900
And let me write one more function, 'subtraction(a,b)',

19
00:00:58,600 --> 00:00:59,600
so 'print

20
00:00:59,600 --> 00:01:02,000
[no audio]

21
00:01:02,000 --> 00:01:10,800
("The subtraction of and is", so simply

22
00:01:10,800 --> 00:01:13,400
.

23
00:01:14,400 --> 00:01:15,400
That's it.

24
00:01:15,600 --> 00:01:18,100
Now, 'None'. Fine.

25
00:01:18,700 --> 00:01:20,300
Now, these are the two functions.

26
00:01:20,300 --> 00:01:22,500
Now, let us assume that we have two variables.

27
00:01:22,500 --> 00:01:26,500
Let's say 'x' equals to some number,

28
00:01:28,800 --> 00:01:30,900
and 'y' equals to some number.

29
00:01:31,400 --> 00:01:35,200
Now, I want to get the addition and subtraction for these two

30
00:01:35,200 --> 00:01:37,400
numbers. So already we defined functions.

31
00:01:37,400 --> 00:01:41,500
That's why simply I am calling 'addition' function by passing

32
00:01:41,500 --> 00:01:44,500
(x,y), and

33
00:01:44,500 --> 00:01:46,400
[no audio]

34
00:01:46,400 --> 00:01:48,500
next time I'm calling 'subtraction' function

35
00:01:48,700 --> 00:01:51,100
simply by calling your 'x' and 'y'. Now

36
00:01:51,100 --> 00:01:52,500
let me save it and run it.

37
00:01:54,100 --> 00:01:55,100
What happened?

38
00:01:55,100 --> 00:01:59,300
[no audio]

39
00:01:59,300 --> 00:02:00,300
Okay.

40
00:02:00,300 --> 00:02:02,400
[no audio]

41
00:02:02,400 --> 00:02:03,500
Spelling mistake.

42
00:02:03,500 --> 00:02:06,300
[no audio]

43
00:02:06,300 --> 00:02:10,100
Now see the result. You're getting 11 and 3. 7 + 4, 11;

44
00:02:10,100 --> 00:02:12,500
7 - 4, 3 you're getting. That's fine.

45
00:02:13,699 --> 00:02:15,800
Now this is your 'script1'. Now

46
00:02:15,800 --> 00:02:18,800
actually I want to write one more script,

47
00:02:20,000 --> 00:02:24,300
but there I want to find addition, subtraction, and multiplication

48
00:02:24,300 --> 00:02:26,600
of two numbers, right?

49
00:02:27,000 --> 00:02:29,800
So what I can do, one thing directly I can copy these two

50
00:02:29,800 --> 00:02:36,600
functions here and I can write one more function simply for multiplication.

51
00:02:36,600 --> 00:02:40,500
[no audio]

52
00:02:40,500 --> 00:02:41,500
Right.

53
00:02:46,500 --> 00:02:51,800
"The multiplication of and is",

54
00:02:53,200 --> 00:02:55,400
simply ''.

55
00:02:55,600 --> 00:02:56,400
That's fine.

56
00:02:57,900 --> 00:03:01,300
But as of now just for your addition and subtraction you

57
00:03:01,300 --> 00:03:02,800
are having very simple lines.

58
00:03:02,900 --> 00:03:05,700
Just assume that you are writing a code in real time.

59
00:03:05,700 --> 00:03:07,600
[no audio]

60
00:03:07,600 --> 00:03:09,100
Right. So there

61
00:03:10,300 --> 00:03:12,700
you have for a function

62
00:03:12,700 --> 00:03:16,600
some hundred lines. First for 'addition' function just assume

63
00:03:16,600 --> 00:03:19,800
that. First 'addition' function you have hundred lines. For

64
00:03:19,800 --> 00:03:21,600
'subtraction' function you have hundred lines.

65
00:03:21,900 --> 00:03:24,900
Then unnecessarily you are going to copy two hundred lines

66
00:03:24,900 --> 00:03:28,100
of code into your current script from your previous script.

67
00:03:28,100 --> 00:03:30,100
[no audio]

68
00:03:30,100 --> 00:03:33,900
Now what I want to do is, I don't want to copy these two functions

69
00:03:33,900 --> 00:03:38,300
here, but I want to use directly from 'script1'. Your

70
00:03:38,300 --> 00:03:39,900
'addition' and 'subtraction' functions

71
00:03:39,900 --> 00:03:42,300
I want to use directly from your 'script1'.

72
00:03:43,000 --> 00:03:47,000
Now, first of all let me give the second script name as

73
00:03:47,000 --> 00:03:48,800
'script2.py'.

74
00:03:50,200 --> 00:03:56,800
Right. Fine. Now, first of all let me define any two variables.

75
00:03:56,800 --> 00:04:01,300
So I am defining 10 and 20, right?

76
00:04:01,300 --> 00:04:05,400
First of all simply I'm finding multiplication of your 'x'

77
00:04:05,400 --> 00:04:07,600
and 'y' from your current script itself.

78
00:04:08,400 --> 00:04:09,900
Yes, you are getting your result.

79
00:04:10,700 --> 00:04:16,399
But now I need to find addition and subtraction of this 'x,y',

80
00:04:16,399 --> 00:04:19,700
I mean 'x' and 'y' variables. So directly I can write

81
00:04:19,700 --> 00:04:23,399
the logic but my intention is if already function is there

82
00:04:23,399 --> 00:04:27,700
in any other script how we can use that in the current script?

83
00:04:28,600 --> 00:04:31,700
Right. So first of all what I am doing is, I am going to comment

84
00:04:31,700 --> 00:04:34,000
these lines, why I will tell you.

85
00:04:35,200 --> 00:04:37,700
But actually you should not disturb other's script, right?

86
00:04:38,000 --> 00:04:41,100
But as of now just I'm commenting. Fine.

87
00:04:41,900 --> 00:04:46,100
Now we are under 'script2', but we want to use the functions

88
00:04:46,100 --> 00:04:47,100
from 'script1'.

89
00:04:47,200 --> 00:04:50,500
So in that case, what you have to do is first of all at very

90
00:04:50,500 --> 00:04:54,500
first line simply you have to write 'import script1'.

91
00:04:55,500 --> 00:04:58,600
Don't write '.py'. 'import script1'.

92
00:04:59,700 --> 00:05:01,000
So this is 'script1', right?

93
00:05:01,000 --> 00:05:02,900
So we are importing 'script1'.

94
00:05:03,800 --> 00:05:04,800
That's it.

95
00:05:05,600 --> 00:05:09,100
Now, let me run it and see the output. There is no error.

96
00:05:10,300 --> 00:05:15,100
Right. Now in 'script1' you have functions anyway, 'addition'

97
00:05:15,100 --> 00:05:17,100
and 'subtraction', right?

98
00:05:17,100 --> 00:05:19,600
So in case if you want to know what are the functions are

99
00:05:19,600 --> 00:05:24,000
there in 'script1' directly you have a logic called 'dir'.

100
00:05:24,900 --> 00:05:28,800
See that 'addition' and 'subtraction' functions are there.

101
00:05:29,900 --> 00:05:34,000
Right. Anyway, we know that what are the functions are there in 'script1'.

102
00:05:34,000 --> 00:05:36,200
[no audio]

103
00:05:36,200 --> 00:05:39,300
Now what I am doing is from 'script1'

104
00:05:39,500 --> 00:05:42,300
I want to call 'addition'. Now

105
00:05:42,300 --> 00:05:47,900
my values are 10, 20. Then what is the result? 10 + 20, addition.

106
00:05:47,900 --> 00:05:48,900
30, you're getting.

107
00:05:50,500 --> 00:05:51,900
Now from 'script1'

108
00:05:51,900 --> 00:05:53,800
I need to call subtraction as well.

109
00:05:56,500 --> 00:05:57,900
Then you are going to get -10.

110
00:05:58,600 --> 00:05:59,600
That's it.

111
00:06:00,000 --> 00:06:04,200
Right. Now, we are not writing any logic for addition and subtraction

112
00:06:04,300 --> 00:06:06,900
in the current script. What we are doing? Already

113
00:06:06,900 --> 00:06:09,800
we have functions for addition and subtraction in another

114
00:06:09,800 --> 00:06:13,400
script, we are trying to use that logic by importing your 'script1'.

115
00:06:14,700 --> 00:06:19,100
So first of all, this is the way how we can use other script

116
00:06:19,100 --> 00:06:20,900
functions in the current script.

117
00:06:20,900 --> 00:06:23,000
[no audio]

118
00:06:23,000 --> 00:06:28,100
That's fine. But while doing this process we did, we commented this code,

119
00:06:28,100 --> 00:06:30,900
but actually you should not comment because that is someone's

120
00:06:31,200 --> 00:06:33,500
code, right? You should not go and disturb that.

121
00:06:35,200 --> 00:06:38,200
Be clear. Now I am going to run our code.

122
00:06:38,200 --> 00:06:39,500
Let me run it only for

123
00:06:39,500 --> 00:06:41,800
[no audio]

124
00:06:41,800 --> 00:06:43,400
'addition', okay.

125
00:06:43,400 --> 00:06:44,900
First of all let me comment it.

126
00:06:44,900 --> 00:06:47,500
[no audio]

127
00:06:47,500 --> 00:06:49,800
So why I'm commenting, you need to get clarity.

128
00:06:51,200 --> 00:06:52,600
Actually, you should not comment.

129
00:06:52,700 --> 00:06:54,700
First of all, let me run this and see the result.

130
00:06:55,100 --> 00:07:00,500
So addition of 10 and 20 is 30 you're getting. Now, this is 'script1'.

131
00:07:01,200 --> 00:07:02,300
Right. Now your script

132
00:07:02,300 --> 00:07:06,000
is there as it is. We uncommented that code, right?

133
00:07:06,000 --> 00:07:09,300
We don't know what is the logic there in 'script1', but we know only

134
00:07:09,500 --> 00:07:11,800
'addition' function is needed from 'script1'.

135
00:07:11,800 --> 00:07:14,800
That's why simply I'm importing 'script1', and I am calling 'addition'

136
00:07:14,800 --> 00:07:17,900
function from that. Now, let me run it and see the result.

137
00:07:19,500 --> 00:07:22,300
Actually, you need only this output but why you are getting

138
00:07:22,300 --> 00:07:23,400
these two lines?

139
00:07:24,400 --> 00:07:26,800
This is for 'script1' purpose, not for us, right.

140
00:07:27,900 --> 00:07:29,700
Whatever the logic, you are getting output, right.

141
00:07:29,700 --> 00:07:32,000
This is for 'script1' purpose, not for us.

142
00:07:32,200 --> 00:07:35,700
We need only 'addition' for 10 and 20.

143
00:07:35,700 --> 00:07:37,600
We need only this output, why you are getting

144
00:07:37,600 --> 00:07:38,900
unnecessarily these two lines?

145
00:07:40,200 --> 00:07:45,000
Right. So that's why generally while implementing Python

146
00:07:45,000 --> 00:07:46,800
Script you need to follow some

147
00:07:48,000 --> 00:07:53,700
procedure, some steps. They are, let me write it. See first of

148
00:07:53,700 --> 00:07:56,600
all guys, what will happen whenever if you try to import any

149
00:07:56,600 --> 00:07:57,900
script or any module?

150
00:07:58,000 --> 00:07:59,600
This is like importing module, right?

151
00:08:01,000 --> 00:08:04,500
See, whenever if you import 'script1' your Python will

152
00:08:04,500 --> 00:08:06,600
go and execute your 'script1' first.

153
00:08:08,000 --> 00:08:10,700
So while executing 'script1
what will happen? This is the

154
00:08:10,700 --> 00:08:13,500
'script1' code. Your Python is going to execute from top to

155
00:08:13,500 --> 00:08:18,000
down. While executing it from top to down in 'script1' also

156
00:08:18,000 --> 00:08:20,000
we have 'addition' and 'subtraction' calling,

157
00:08:20,700 --> 00:08:22,800
so that's why you're going to get output for these two.

158
00:08:23,900 --> 00:08:26,500
But we don't want that. In our current script

159
00:08:26,500 --> 00:08:28,500
we don't want that, right?

160
00:08:29,100 --> 00:08:35,100
So that's why generally while implementing any script, right,

161
00:08:35,100 --> 00:08:38,700
you have to write some 'main' function, inside of that 'main' function

162
00:08:38,700 --> 00:08:40,700
[no audio]

163
00:08:40,700 --> 00:08:43,700
you need to execute your main logic.

164
00:08:43,700 --> 00:08:48,900
[no audio]

165
00:08:48,900 --> 00:08:52,700
So this is first of all standard way to write scripts

166
00:08:53,100 --> 00:08:55,200
using Python. Right. Now

167
00:08:55,200 --> 00:08:59,200
we are calling 'main'. Even though if you do this still you're

168
00:08:59,200 --> 00:09:00,800
going to get same output. Observe that.

169
00:09:02,000 --> 00:09:05,600
Now I am running, rerunning. See the result. Unnecessarily you're

170
00:09:05,600 --> 00:09:10,100
getting two lines of code, extra code, but I want to get only this line.

171
00:09:11,000 --> 00:09:13,800
I don't want these two lines, right?

172
00:09:14,100 --> 00:09:17,500
So that's why what I am doing is, while calling 'main' function in

173
00:09:17,500 --> 00:09:19,600
'script1' I am writing a simple logic.

174
00:09:19,600 --> 00:09:24,000
[no audio]

175
00:09:24,000 --> 00:09:25,800
Don't worry, first observe the output.

176
00:09:25,800 --> 00:09:32,300
[no audio]

177
00:09:32,300 --> 00:09:33,900
Right. Now see the result.

178
00:09:33,900 --> 00:09:37,800
I am running. Now, you are not getting your 'script1' output.

179
00:09:37,900 --> 00:09:41,500
You are getting only from 'script2' output. This is what we need.

180
00:09:41,500 --> 00:09:44,100
[no audio]

181
00:09:44,100 --> 00:09:47,300
Right. The same way whenever if you are writing code, you

182
00:09:47,300 --> 00:09:50,200
need to follow this structure for your Python,

183
00:09:50,800 --> 00:09:53,100
then that is a good Python script. That's it.

184
00:09:53,100 --> 00:09:54,100
Nothing is there.

185
00:09:54,100 --> 00:09:57,500
[no audio]

186
00:09:57,500 --> 00:10:01,500
So how you are going to overcome getting output from 'script1'?

187
00:10:01,500 --> 00:10:03,400
I will show you, I will explain that.

188
00:10:03,400 --> 00:10:09,500
[no audio]

189
00:10:09,500 --> 00:10:10,500
Now,

190
00:10:17,100 --> 00:10:18,100
that's it.

191
00:10:18,100 --> 00:10:21,200
[no audio]

192
00:10:21,200 --> 00:10:24,800
See that. And go to your 'script1', and run your 'script1'.

193
00:10:24,800 --> 00:10:26,900
So you're going to get your 'script1' output as well.

194
00:10:28,200 --> 00:10:30,700
There is no change in the output. It's working perfectly.

195
00:10:32,200 --> 00:10:37,800
Right. So now you need to understand about name variable,

196
00:10:37,800 --> 00:10:40,300
'__name__'.

197
00:10:41,700 --> 00:10:48,700
Right. Fine. Now, see. First let me comment entire code in your

198
00:10:48,700 --> 00:10:51,200
'script1' as well as in 'script2'.

199
00:10:51,200 --> 00:11:00,300
[no audio]

200
00:11:00,300 --> 00:11:03,200
Now what I am doing is simply I am printing

201
00:11:03,200 --> 00:11:06,600
[no audio]

202
00:11:06,600 --> 00:11:11,000
'__name', that is a variable like 'x', predefined

203
00:11:11,000 --> 00:11:12,100
variable, right?

204
00:11:12,200 --> 00:11:15,200
I am running. See the result what you are getting. '__main__'. The

205
00:11:15,200 --> 00:11:19,500
same way that variable, even I am trying to print from

206
00:11:19,500 --> 00:11:21,000
your second script as well.

207
00:11:21,000 --> 00:11:23,600
[no audio]

208
00:11:23,600 --> 00:11:25,400
You're getting '__main__', right.

209
00:11:25,800 --> 00:11:27,100
Now, what I am doing is,

210
00:11:28,800 --> 00:11:29,800
this is

211
00:11:31,000 --> 00:11:35,500
from 'script1', right. Now, let me run it.

212
00:11:35,900 --> 00:11:36,900
Yes, that's fine.

213
00:11:37,300 --> 00:11:40,700
Now, same way I am trying to write here,

214
00:11:42,200 --> 00:11:45,600
"This is from script2".

215
00:11:51,800 --> 00:11:53,900
Now, let me run it. Fine.

216
00:11:53,900 --> 00:11:58,400
So whenever if you're running your 'script2', and

217
00:11:58,400 --> 00:12:01,000
if you are printing '__name' variable value

218
00:12:01,000 --> 00:12:04,000
you're getting '__main__', or in 'script1'

219
00:12:04,000 --> 00:12:06,400
also whenever if you try to print '__name'

220
00:12:06,400 --> 00:12:08,300
'__name' variable value

221
00:12:08,300 --> 00:12:10,400
you are getting '__main__' only with underscores.

222
00:12:11,600 --> 00:12:12,600
Right. That's fine.

223
00:12:13,200 --> 00:12:17,300
Now, what I am doing is, I am trying to 'import script1'.

224
00:12:17,300 --> 00:12:22,500
[no audio]

225
00:12:22,500 --> 00:12:27,600
Right. See whenever if you 'import script1' first what your

226
00:12:27,600 --> 00:12:31,000
Python will do means, your Python will go and execute completely

227
00:12:31,000 --> 00:12:35,100
'script1' because of this line. Because of this line your

228
00:12:35,100 --> 00:12:38,400
Python will go and execute your 'script1' first completely.

229
00:12:39,700 --> 00:12:41,500
Right. First observe the output.

230
00:12:41,500 --> 00:12:43,500
[no audio]

231
00:12:43,500 --> 00:12:45,500
"This is from script1", but

232
00:12:45,500 --> 00:12:48,900
what you are getting? You are getting 'script1' not 'main'

233
00:12:50,000 --> 00:12:53,900
And because of this line, this is from 'script2', you

234
00:12:53,900 --> 00:13:00,700
are getting 'main'. That means whenever if you run any script

235
00:13:00,700 --> 00:13:05,400
directly, then 'name' variable value equals to 'main' with underscores.

236
00:13:06,600 --> 00:13:08,300
The variable name is 'main'.

237
00:13:09,400 --> 00:13:14,600
But we are running this 'name', this code indirectly from 'script2'

238
00:13:14,600 --> 00:13:18,500
right. 'script1' means, your 'import script1' means

239
00:13:18,500 --> 00:13:20,700
you are running 'script1' code, but you are running

240
00:13:20,700 --> 00:13:24,700
indirectly from 'script2', you're not running directly 'script1'.

241
00:13:25,100 --> 00:13:28,200
We are not running this code directly. 'script2' is running

242
00:13:28,200 --> 00:13:31,800
'script1' code. In that case that 'name' variable value

243
00:13:31,800 --> 00:13:35,100
is equals to 'script1', not 'main.

244
00:13:36,300 --> 00:13:37,300
Be clear.

245
00:13:38,500 --> 00:13:43,300
If you run simply your code directly, and in that case your

246
00:13:43,300 --> 00:13:50,300
variable value is 'main', but if you run any code indirectly,

247
00:13:50,500 --> 00:13:53,600
if you observe here 'import script1' is running because

248
00:13:53,600 --> 00:13:56,100
of 'script2', while running 'script2' you're also running

249
00:13:56,100 --> 00:13:59,200
'script1'. That means 'script2' is running 'script1'.

250
00:13:59,400 --> 00:14:02,900
You're not directly running 'script1'. So at that time whatever

251
00:14:02,900 --> 00:14:06,300
the variable is there inside of 'script1' that variable,

252
00:14:06,300 --> 00:14:11,600
'name' variable value will become the name of that script, right.

253
00:14:12,100 --> 00:14:14,300
Now, observe here.

254
00:14:14,300 --> 00:14:17,600
[no audio]

255
00:14:17,600 --> 00:14:19,200
Now, let me comment this code.

256
00:14:20,900 --> 00:14:26,000
Now because of 'import script1' what will happen? Your code

257
00:14:26,000 --> 00:14:27,400
will run from top to down.

258
00:14:27,400 --> 00:14:29,600
[no audio]

259
00:14:29,600 --> 00:14:35,400
Because of 'script1', 'import script1', I mean from 'script2'

260
00:14:35,400 --> 00:14:38,800
you are importing 'script1'. Whenever if you do 'import

261
00:14:38,800 --> 00:14:41,400
script1', at the time what will happen? Your Python will

262
00:14:41,400 --> 00:14:46,100
run first entire 'script1', right. Now observe that. In

263
00:14:46,100 --> 00:14:49,600
'script1' what we have? So while running your 'script1'

264
00:14:49,600 --> 00:14:50,600
from top to down

265
00:14:51,800 --> 00:14:55,300
function, anyway your Python won't execute as of now, function,

266
00:14:55,700 --> 00:14:59,100
your Python won't execute as of now, function again,

267
00:14:59,100 --> 00:15:00,900
your Python won't execute as of now. Simply

268
00:15:00,900 --> 00:15:03,600
it will remember all these three functions. Now,

269
00:15:03,600 --> 00:15:08,200
this is the 'main' line, 'if __name', so you

270
00:15:08,200 --> 00:15:09,400
are not running directly

271
00:15:09,400 --> 00:15:11,800
this 'script1'. Your 'script2' is running,

272
00:15:11,800 --> 00:15:15,000
that's why 'name' value is equal to 'script1'.

273
00:15:16,100 --> 00:15:21,700
Now this is equals to 'script1', not 'main' now, right. If it is 'script1'

274
00:15:21,700 --> 00:15:24,300
then they are not equal, right? This value and this value,

275
00:15:24,300 --> 00:15:28,000
they are not equal. If they are not equal then 'if' doesn't

276
00:15:28,000 --> 00:15:29,600
allow to execute 'main' function.

277
00:15:30,000 --> 00:15:32,100
It doesn't allow to call 'main' function.

278
00:15:32,400 --> 00:15:35,900
If you are not calling 'main' function, then you are not calling these lines.

279
00:15:35,900 --> 00:15:38,000
If you are not calling these lines, then you are not getting

280
00:15:38,000 --> 00:15:40,400
any output from function one,

281
00:15:40,400 --> 00:15:43,000
sorry from 'script1' in 'script2'.

282
00:15:43,800 --> 00:15:45,400
That's it. So that you are going to,

283
00:15:45,400 --> 00:15:47,400
[no audio]

284
00:15:47,400 --> 00:15:48,600
what you're doing? So that

285
00:15:48,600 --> 00:15:52,400
you are going to avoid getting output from 'script1'.

286
00:15:53,200 --> 00:15:56,700
So you are going to get output only whenever if you call functions.

287
00:15:56,700 --> 00:15:59,100
[no audio]

288
00:15:59,100 --> 00:16:01,500
Right. Now, see that.

289
00:16:02,700 --> 00:16:07,300
Now we are on 'script2', so whenever if you run your Python

290
00:16:07,300 --> 00:16:10,600
Script, what will happen? Very first line 'import'. Yes, that will

291
00:16:10,600 --> 00:16:14,200
execute. 'import script1' is nothing but you are going to run 'script1'.

292
00:16:14,800 --> 00:16:16,000
Anyway, you know in 'script1'

293
00:16:16,000 --> 00:16:17,100
what is the logic there,

294
00:16:18,400 --> 00:16:19,400
right?

295
00:16:21,600 --> 00:16:25,800
Then after execution of all the code from top to down

296
00:16:25,800 --> 00:16:28,200
what your Python will do? Simply your Python will remember

297
00:16:28,200 --> 00:16:29,900
all the functions names.

298
00:16:30,800 --> 00:16:32,700
That's it. Then it will come back to 'script1'.

299
00:16:33,700 --> 00:16:35,000
Now in 'script1'

300
00:16:35,000 --> 00:16:36,600
we defined one multiple,

301
00:16:36,600 --> 00:16:40,900
I mean 'multiplication' function, one 'main' function, right but

302
00:16:40,900 --> 00:16:44,900
be clear, already you know 'main' function from here, but that

303
00:16:44,900 --> 00:16:48,300
is from 'script1', not from 'script2'. Now this is from 'script2'.

304
00:16:48,300 --> 00:16:50,000
Your Python can distinguish that.

305
00:16:51,700 --> 00:16:53,700
Then after that you have

306
00:16:53,700 --> 00:16:57,000
'main'. 'if __name__ == "__main__"'.

307
00:16:57,000 --> 00:17:00,200
[no audio]

308
00:17:00,200 --> 00:17:06,300
Right. Now you are running 'script2' directly, that's why 'name'

309
00:17:06,300 --> 00:17:09,098
variable if it is equal to 'main', both are equal.

310
00:17:09,098 --> 00:17:12,700
If both are equal your 'if' condition will allow to execute

311
00:17:12,700 --> 00:17:18,098
this 'main'. Then you are coming to here. Then 'x = 10',

312
00:17:18,098 --> 00:17:21,900
'y = 10'. Then from 'script1' you're calling 'addition'.

313
00:17:22,598 --> 00:17:26,000
Now your Python will go to 'script1', and there it will try to

314
00:17:26,000 --> 00:17:29,599
execute 'addition' function, then we'll come back to here. That's it.

315
00:17:29,599 --> 00:17:34,599
[no audio]

316
00:17:34,599 --> 00:17:36,400
That's it. So now,

317
00:17:37,700 --> 00:17:40,099
by doing in this way what we are doing?

318
00:17:40,099 --> 00:17:42,200
[no audio]

319
00:17:42,200 --> 00:17:46,099
If you observe, 'script1' is now a module for your 'script2'.

320
00:17:46,099 --> 00:17:48,099
That's why you are importing 'script1' here.

321
00:17:48,099 --> 00:17:50,099
[no audio]

322
00:17:50,099 --> 00:17:51,300
Right. So

323
00:17:51,300 --> 00:17:55,600
guys, now, from now onwards while going forward whenever if

324
00:17:55,600 --> 00:17:57,900
you're trying to import your, sorry whenever if you are

325
00:17:57,900 --> 00:18:01,700
trying to create any Python Script, now you need to follow

326
00:18:01,700 --> 00:18:05,300
this structure. That is in case if you want to import anything

327
00:18:05,300 --> 00:18:06,400
you can import here,

328
00:18:06,600 --> 00:18:12,000
some 'sys', 'os', or 'time', some modules, or you can also import

329
00:18:12,000 --> 00:18:19,800
line-by-line. 'import os'. 'import time'. Right. 'import datetime' module.

330
00:18:20,200 --> 00:18:21,200
Let me save it.

331
00:18:21,200 --> 00:18:24,400
[no audio]

332
00:18:24,400 --> 00:18:36,700
'newstructureforpythonscript.py'. Right. Then after

333
00:18:36,700 --> 00:18:42,500
that very first line is always you try to import, you try to write in this way.

334
00:18:42,500 --> 00:18:48,800
'If __name__ == "__main__"underscore

335
00:18:49,000 --> 00:18:52,400
then call 'main' function. Now try to define somewhere your

336
00:18:52,400 --> 00:18:56,400
'main' function. Now from here onwards try to write your main

337
00:18:56,400 --> 00:18:59,900
logic. Suppose I want to find the addition of any numbers,

338
00:18:59,900 --> 00:19:03,500
let's say 'x = 1', 'y = 2'. Now directly

339
00:19:03,500 --> 00:19:06,600
I don't want to find, or if you want to directly find, yes

340
00:19:07,000 --> 00:19:10,400
simply write 'x + y'. That's it.

341
00:19:10,400 --> 00:19:12,000
Sorry 'x + y'.

342
00:19:12,000 --> 00:19:14,400
[no audio]

343
00:19:14,400 --> 00:19:16,200
Then simply, this is a function

344
00:19:16,200 --> 00:19:17,000
that's why at the end

345
00:19:17,000 --> 00:19:18,100
just write 'return None'.

346
00:19:19,000 --> 00:19:20,000
That's it.

347
00:19:20,800 --> 00:19:23,500
But I don't want to directly write my addition here, then

348
00:19:23,500 --> 00:19:27,700
just try to define one function for that, 'addition(x,y)'.

349
00:19:27,700 --> 00:19:33,700
Somewhere just write 'addition(a,b)'. Then try

350
00:19:33,700 --> 00:19:45,200
to print, "The addition of your and is simply

351
00:19:45,200 --> 00:19:47,800
''. That's it.

352
00:19:48,200 --> 00:19:49,500
So I'm not returning anything.

353
00:19:49,500 --> 00:19:51,700
Simply write 'return None'.

354
00:19:52,000 --> 00:19:53,500
That's it. Now see the result.

355
00:19:53,500 --> 00:19:54,700
We are getting same output.

356
00:19:54,700 --> 00:19:56,900
[no audio]

357
00:19:56,900 --> 00:20:01,200
Right. So guys while going forward, please follow this structure.

358
00:20:01,300 --> 00:20:04,700
Always try to start with your code with 'if' condition,

359
00:20:04,700 --> 00:20:10,800
'if __name__== "__main__", then call 'main' function, and

360
00:20:10,800 --> 00:20:13,000
try to write your logic from 'main' function.

361
00:20:14,200 --> 00:20:17,600
So what is the advantage by writing this means, whenever if

362
00:20:17,600 --> 00:20:21,800
you are trying to import this code into other scripts at

363
00:20:21,800 --> 00:20:25,000
that time you are avoiding execution of your 'main' block.

364
00:20:24,800 --> 00:20:26,800
[no audio]

365
00:20:26,800 --> 00:20:30,100
In case if you don't write this logic, unnecessarily you are

366
00:20:30,100 --> 00:20:32,900
going to execute your code in other scripts.

367
00:20:32,900 --> 00:20:36,200
[no audio]

368
00:20:36,200 --> 00:20:40,500
Right. So, so that's why while going forward we are trying to follow

369
00:20:40,500 --> 00:20:43,000
this structure while writing Python Scripts.

370
00:20:44,200 --> 00:20:46,500
Right. If you write in this way, then this is nothing but

371
00:20:46,700 --> 00:20:51,700
creation of your own modules, or you are defining your required

372
00:20:51,700 --> 00:20:54,400
modules, or this is called user-defined module.

373
00:20:54,700 --> 00:20:56,200
That's it. Simple way

374
00:20:56,200 --> 00:20:57,200
I'm explaining here.

375
00:21:00,900 --> 00:21:02,900
Okay guys, thank you for watching this video.

376
00:21:02,900 --> 00:21:10,400
[no audio]