String-1 completed

akiltipu · akiltipu · commit ec79024b8c83 · 2019-09-03T22:56:20.000+06:00
diff --git a/String-1/combo_string.py b/String-1/combo_string.py
@@ -0,0 +1,15 @@
+# Given 2 strings, a and b, 
+# return a string of the form short+long+short, 
+# with the shorter string on the outside and the longer string on the inside. 
+# The strings will not be the same length, but they may be empty (length 0).
+
+
+# combo_string('Hello', 'hi') → 'hiHellohi'
+# combo_string('hi', 'Hello') → 'hiHellohi'
+# combo_string('aaa', 'b') → 'baaab'
+
+def combo_string(a, b):
+    if len(a) > len(b):
+        return b + a + b
+    else:
+        return a + b + a
diff --git a/String-1/extra_end.py b/String-1/extra_end.py
@@ -0,0 +1,10 @@
+# Given a string, return a new string made of 3 copies of the last 2 chars of the original string. 
+# The string length will be at least 2.
+
+
+# extra_end('Hello') → 'lololo'
+# extra_end('ab') → 'ababab'
+# extra_end('Hi') → 'HiHiHi'
+
+def extra_end(str):
+    return (str[-2] + str[-1]) * 3
diff --git a/String-1/first_half.py b/String-1/first_half.py
@@ -0,0 +1,10 @@
+# Given a string of even length, return the first half. 
+# So the string "WooHoo" yields "Woo".
+
+# first_half('WooHoo') → 'Woo'
+# first_half('HelloThere') → 'Hello'
+# first_half('abcdef') → 'abc'
+
+def first_half(str):
+    h = len(str) / 2
+    return str[: h]
diff --git a/String-1/first_two.py b/String-1/first_two.py
@@ -0,0 +1,16 @@
+# Given a string, return the string made of its first two chars, 
+# so the String "Hello" yields "He". 
+# If the string is shorter than length 2, 
+# return whatever there is, so "X" yields "X", 
+# and the empty string "" yields the empty string "".
+
+
+# first_two('Hello') → 'He'
+# first_two('abcdefg') → 'ab'
+# first_two('ab') → 'ab'
+
+def first_two(str):
+    if len(str) <= 2:
+        return str
+    else:
+        return str[0] + str[1]
diff --git a/String-1/hello_name.py b/String-1/hello_name.py
@@ -0,0 +1,12 @@
+# Given a string name, e.g. "Bob", 
+# return a greeting of the form "Hello Bob!".
+
+
+# hello_name('Bob') → 'Hello Bob!'
+# hello_name('Alice') → 'Hello Alice!'
+# hello_name('X') → 'Hello X!'
+
+def hello_name(name):
+    s = "Hello " + name + "!"
+    return s
+    #return "Hello " + name + "!"
diff --git a/String-1/left2.py b/String-1/left2.py
@@ -0,0 +1,11 @@
+# Given a string, return a "rotated left 2" 
+# version where the first 2 chars are moved to the end. 
+# The string length will be at least 2.
+
+
+# left2('Hello') → 'lloHe'
+# left2('java') → 'vaja'
+# left2('Hi') → 'Hi'
+
+def left2(str):
+    return str[2:] + str[:2]
diff --git a/String-1/make_abba.py b/String-1/make_abba.py
@@ -0,0 +1,11 @@
+# Given two strings, a and b,
+# return the result of putting them together in the order abba, 
+# e.g. "Hi" and "Bye" returns "HiByeByeHi".
+
+
+# make_abba('Hi', 'Bye') → 'HiByeByeHi'
+# make_abba('Yo', 'Alice') → 'YoAliceAliceYo'
+# make_abba('What', 'Up') → 'WhatUpUpWhat'
+
+def make_abba(a, b):
+    return a + b * 2 + a
diff --git a/String-1/make_out_word.py b/String-1/make_out_word.py
@@ -0,0 +1,12 @@
+# Given an "out" string length 4, 
+# such as "<<>>", and a word, 
+# return a new string where the word is in the middle of the out string,
+# e.g. "<<word>>".
+
+
+# make_out_word('<<>>', 'Yay') → '<<Yay>>'
+# make_out_word('<<>>', 'WooHoo') → '<<WooHoo>>'
+# make_out_word('[[]]', 'word') → '[[word]]'
+
+def make_out_word(out, word):
+    return out[0] + out[1] + word + out[2] + out[3]
diff --git a/String-1/make_tags.py b/String-1/make_tags.py
@@ -0,0 +1,13 @@
+# The web is built with HTML strings like "<i>Yay</i>" 
+# which draws Yay as italic text. In this example, 
+# the "i" tag makes <i> and </i> which surround the word "Yay". 
+# Given tag and word strings, create the HTML string with tags around the word, 
+# e.g. "<i>Yay</i>".
+
+
+# make_tags('i', 'Yay') → '<i>Yay</i>'
+# make_tags('i', 'Hello') → '<i>Hello</i>'
+# make_tags('cite', 'Yay') → '<cite>Yay</cite>'
+
+def make_tags(tag, word):
+    return "<" + tag + ">" + word + "</" + tag + ">"
diff --git a/String-1/non_start.py b/String-1/non_start.py
@@ -0,0 +1,12 @@
+# Given 2 strings, return their concatenation, 
+# except omit the first char of each. 
+# The strings will be at least length 1.
+
+
+# non_start('Hello', 'There') → 'ellohere'
+# non_start('java', 'code') → 'avaode'
+# non_start('shotl', 'java') → 'hotlava'
+
+
+def non_start(a, b):
+    return a[1:] + b[1:]
diff --git a/String-1/without_end.py b/String-1/without_end.py
@@ -0,0 +1,10 @@
+# Given a string, return a version without the first and last char, 
+# so "Hello" yields "ell". The string length will be at least 2.
+
+
+# without_end('Hello') → 'ell'
+# without_end('java') → 'av'
+# without_end('coding') → 'odin'
+
+def without_end(str):
+    return str[1 : -1]
