Add format strings

Author: hermite2053

io/format_strings/format_index.py

@@ -0,0 +1,2 @@
+print('{0}, {1}, {2}'.format('A', 'B', 'C'))
+print('{2}, {0}, {1}, {2}'.format('A', 'B', 'C'))

io/format_strings/format_keyword.py

@@ -0,0 +1 @@
+print('Made in {place}'.format(place='Japan'))

io/format_strings/format_position.py

@@ -0,0 +1,5 @@
+x = 4142135
+y = 7320508
+
+print('x: {:-9}  {:2.2%}'.format(x, x / (x + y)))
+print('y: {:-9}  {:2.2%}'.format(y, y / (x + y)))

io/format_strings/format_with_hand.py

@@ -0,0 +1,4 @@
+import math
+
+for i in range(1, 11):
+    print(repr(i).rjust(2), '\b! =', repr(math.factorial(i)).rjust(12))

io/format_strings/formatted_str.py

@@ -0,0 +1,5 @@
+year = 2020
+place = 'Tokyo'
+
+# Begin with `f` of `F` to use formatted string literals.
+print(f'{place} {year}')

io/format_strings/str.py

@@ -0,0 +1,9 @@
+a = 'Hello, world!'
+print(a)
+print(str(a))
+print(repr(a))
+
+b = 1/7
+print(b)
+print(str(b))
+print(repr(b))