1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
\documentclass[14pt,compress,aspectratio=169]{beamer}
\input{macros.tex}
\title[*args, **kw]{Advanced Python}
\subtitle{Arbitrary arguments for functions}
\author[FOSSEE] {The FOSSEE Group}
\institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay}
\date[] {Mumbai, India}
\begin{document}
\begin{frame}
\titlepage
\end{frame}
\begin{frame}
\frametitle{Overview}
\begin{itemize}
\item Advanced unpacking
\item Variable arguments
\item Arbitrary keyword arguments
\item Unpacking arguments
\end{itemize}
\end{frame}
\begin{frame}[fragile]
\frametitle{Advanced unpacking}
\vspace*{-0.1in}
\begin{lstlisting}
In []: a, b = 1, 2 # We know this!
\end{lstlisting}
\pause
\begin{itemize}
\item In Python 3.x we can also do
\end{itemize}
\begin{lstlisting}
In []: first, *rest = range(5)
In []: first
Out[]: 0
In []: first, *middle, last = range(5)
In []: middle
Out[]: [1, 2, 3]
\end{lstlisting}
\end{frame}
\begin{frame}[fragile]
\frametitle{Advanced unpacking ...}
\begin{itemize}
\item Also works for files
\end{itemize}
\begin{lstlisting}
In []: f = open('file.txt')
In []: first, *ign, last = f.readlines()
In []: f.close()
\end{lstlisting}
\end{frame}
\begin{frame}[fragile]
\frametitle{Arbitrary positional arguments}
\vspace*{-0.1in}
\begin{itemize}
\item Arbitrary positional arguments: \lstinline{*arg}
\end{itemize}
\begin{lstlisting}
In []: def func(a, b, *args):
...: print(a, b, args)
\end{lstlisting}
\pause
\begin{lstlisting}
In []: func(1, 2)
1 2 ()
In []: func(1, 2, 'a')
1 2 ('a',)
In []: func(1, 2, 3, 'a')
1 2 (3, 'a')
\end{lstlisting}
\end{frame}
\begin{frame}[fragile]
\frametitle{Arbitrary positional arguments}
Nothing special about \lstinline{args}:
\begin{lstlisting}
In []: def func(a, b, *rest):
...: print(a, b, rest)
\end{lstlisting}
Also is perfectly valid
\end{frame}
\begin{frame}[fragile]
\frametitle{Arbitrary keyword arguments}
\vspace*{-0.1in}
\begin{itemize}
\item Keyword arguments using \lstinline{**kw}
\end{itemize}
\begin{lstlisting}
In []: def func(a, b='b', **kw):
...: print(a, b, kw)
\end{lstlisting}
\pause
\begin{lstlisting}
In []: func(1)
1 b {}
In []: func(1, 2)
1 2 {}
In []: func(1, b=2)
1 2 {}
\end{lstlisting}
\end{frame}
\begin{frame}[fragile]
\frametitle{Arbitrary keyword arguments}
\begin{lstlisting}
In []: def func(a, b='b', **k):
...: print(a, b, k)
In []: func(1, c=3)
1 b {'c': 3}
In []: func(1, c=3, d=4)
1 b {'c': 3, 'd': 4}
\end{lstlisting}
\end{frame}
\begin{frame}[fragile]
\frametitle{Argument unpacking}
\begin{lstlisting}
In []: def func(a, b):
...: print(a, b)
In []: func(*[5, 10])
5 10
In []: func(*(5, 10))
5 10
\end{lstlisting}
\end{frame}
\begin{frame}[fragile]
\frametitle{Argument unpacking ...}
\begin{lstlisting}
In []: def func(a=1, b=2):
...: print(a, b)
In []: func(**{'a':5, 'b':10})
5 10
In []: func(**dict(a=5, b=10))
5 10
\end{lstlisting}
\end{frame}
\begin{frame}[fragile]
\frametitle{Summary}
\begin{itemize}
\item Advanced unpacking
\item Arbitrary positional arguments with \lstinline{*args}
\item Arbitrary keyword arguments with \lstinline{**kw}
\item Argument unpacking
\end{itemize}
\end{frame}
\end{document}
|
