diff --git a/addons/cert.py b/addons/cert.py
index 8f1abf2d4..fc397b133 100644
--- a/addons/cert.py
+++ b/addons/cert.py
@@ -26,7 +26,7 @@ def isUnpackedStruct(var):
             if structScope:
                 linenr = int(structScope.classStart.linenr)
                 for line in open(structScope.classStart.file):
-                    linenr = linenr - 1
+                    linenr -= 1
                     if linenr == 0:
                         return True
                     if re.match(r'#pragma\s+pack\s*\(', line):
diff --git a/addons/cppcheckdata.py b/addons/cppcheckdata.py
index 673a04a44..aea45b8bc 100644
--- a/addons/cppcheckdata.py
+++ b/addons/cppcheckdata.py
@@ -642,7 +642,7 @@ def astIsFloat(token):
         return False
     if token.str == '.':
         return astIsFloat(token.astOperand2)
-    if '+-*/%'.find(token.str) == 0:
+    if token.str in '+-*/%':
         return astIsFloat(token.astOperand1) or astIsFloat(token.astOperand2)
     if not token.variable:
         # float literal?
diff --git a/addons/misra.py b/addons/misra.py
index 5093a857d..563808ced 100644
--- a/addons/misra.py
+++ b/addons/misra.py
@@ -223,7 +223,7 @@ def isUnsignedInt(expr):
     if not expr:
         return False
     if expr.isNumber:
-        return expr.str.find('u') > 0 or expr.str.find('U') > 0
+        return 'u' in expr.str or 'U' in expr.str
     if expr.str in {'+', '-', '*', '/', '%'}:
         return isUnsignedInt(expr.astOperand1) or isUnsignedInt(expr.astOperand2)
     return False
@@ -811,7 +811,7 @@ def misra_16_3(rawTokens):
             else:
                 state = 0
         elif token.str.startswith('/*') or token.str.startswith('//'):
-            if token.str.lower().find('fallthrough') > 0:
+            if 'fallthrough' in token.str.lower():
                 state = 2
         elif token.str == '{':
             state = 2
@@ -956,7 +956,7 @@ def misra_20_2(data):
         if not directive.str.startswith('#include '):
             continue
         for pattern in {'\\', '//', '/*', "'"}:
-            if directive.str.find(pattern) > 0:
+            if pattern in directive.str:
                 reportError(directive, 20, 2)
                 break
 
diff --git a/test/synthetic/report.py b/test/synthetic/report.py
index adc74c54d..e4d972102 100755
--- a/test/synthetic/report.py
+++ b/test/synthetic/report.py
@@ -23,10 +23,8 @@ def parsefile(filename):
             functionName = res.group(1)
         if line.startswith('}'):
             functionName = ''
-        elif line.find('BUG') > 0 or line.find('WARN') > 0 or filename == 'ub.c':
-            spaces = ''
-            for i in range(100):
-                spaces = spaces + ' '
+        elif 'BUG' in line or 'WARN' in line or filename == 'ub.c':
+            spaces = ' ' * 100
             s = filename + spaces
             s = s[:15] + str(linenr) + spaces
             s = s[:20] + functionName + spaces
diff --git a/tools/daca2-addons.py b/tools/daca2-addons.py
index f66e0448e..0f86571ae 100644
--- a/tools/daca2-addons.py
+++ b/tools/daca2-addons.py
@@ -53,7 +53,7 @@ def getpackages(folder):
             filename = None
         elif line[:13 + len(folder)] == './pool/main/' + folder + '/':
             path = line[2:-1]
-        elif path and line.find('.orig.tar.') > 0:
+        elif path and '.orig.tar.' in line:
             filename = line[1 + line.rfind(' '):]
 
     for a in archives:
@@ -75,7 +75,7 @@ def handleRemoveReadonly(func, path, exc):
 def removeAllExceptResults():
     count = 5
     while count > 0:
-        count = count - 1
+        count -= 1
 
         filenames = []
         for g in glob.glob('[A-Za-z0-9]*'):
@@ -116,7 +116,7 @@ def removeLargeFiles(path):
             removeLargeFiles(g + '/')
         elif os.path.isfile(g) and g[-4:] != '.txt':
             statinfo = os.stat(g)
-            if path.find('/clang/INPUTS/') > 0 or statinfo.st_size > 100000:
+            if '/clang/INPUTS/' in path or statinfo.st_size > 100000:
                 os.remove(g)
 
 
@@ -194,7 +194,7 @@ def scanarchive(filepath, jobs):
     addons = sorted(glob.glob(os.path.expanduser('~/cppcheck/addons/*.py')))
     for dumpfile in sorted(dumpfiles('')):
         for addon in addons:
-            if addon.find('cppcheckdata.py') > 0:
+            if 'cppcheckdata.py' in addon:
                 continue
 
             p2 = subprocess.Popen(['nice',
diff --git a/tools/daca2-download.py b/tools/daca2-download.py
index 80d435d61..1b1e68c29 100644
--- a/tools/daca2-download.py
+++ b/tools/daca2-download.py
@@ -52,7 +52,7 @@ def getpackages():
             filename = None
         elif line[:12] == './pool/main/':
             path = line[2:-1]
-        elif path and line.find('.orig.tar.') > 0:
+        elif path and '.orig.tar.' in line:
             filename = line[1 + line.rfind(' '):]
 
     for a in archives:
@@ -74,7 +74,7 @@ def handleRemoveReadonly(func, path, exc):
 def removeAll():
     count = 5
     while count > 0:
-        count = count - 1
+        count -= 1
 
         filenames = []
         for g in glob.glob('[#_A-Za-z0-9]*'):
diff --git a/tools/daca2-report.py b/tools/daca2-report.py
index 51337204d..fec676d1b 100644
--- a/tools/daca2-report.py
+++ b/tools/daca2-report.py
@@ -10,26 +10,26 @@ def readdate(data):
     else:
         datepos = data.find('\nDATE ')
         if datepos >= 0:
-            datepos = datepos + 1
+            datepos += 1
 
     if datepos < 0:
         return None
 
     datestr = ''
-    datepos = datepos + 5
+    datepos += 5
     while True:
         if datepos >= len(data):
             return None
         d = data[datepos]
         if d >= '0' and d <= '9':
-            datestr = datestr + d
+            datestr += d
         elif d == '\n' or d == '\r':
             if len(datestr) == 8:
                 return datestr[:4] + '-' + datestr[4:6] + '-' + datestr[6:]
             return None
         elif d != ' ' and d != '-':
             return None
-        datepos = datepos + 1
+        datepos += 1
 
 daca2folder = os.path.expanduser('~/daca2/')
 path = ''
@@ -37,11 +37,11 @@ for arg in sys.argv[1:]:
     if arg.startswith('--daca2='):
         daca2folder = arg[8:]
         if daca2folder[-1] != '/':
-            daca2folder = daca2folder + '/'
+            daca2folder += '/'
     else:
         path = arg
         if path[-1] != '/':
-            path = path + '/'
+            path += '/'
 
 mainpage = open(path + 'daca2.html', 'wt')
 mainpage.write('<!DOCTYPE html>\n')
diff --git a/tools/daca2.py b/tools/daca2.py
index 0a4cea24e..506b74da2 100644
--- a/tools/daca2.py
+++ b/tools/daca2.py
@@ -55,7 +55,7 @@ def getpackages(folder):
             filename = None
         elif line[:13 + len(folder)] == './pool/main/' + folder + '/':
             path = line[2:-1]
-        elif path and line.find('.orig.tar.') > 0:
+        elif path and '.orig.tar.' in line:
             filename = line[1 + line.rfind(' '):]
 
     for a in archives:
@@ -82,7 +82,7 @@ def removeAllExceptResults():
     for filename in filenames:
         count = 5
         while count > 0:
-            count = count - 1
+            count -= 1
 
             try:
                 if os.path.isdir(filename):
diff --git a/tools/matchcompiler.py b/tools/matchcompiler.py
index 92ec203a2..32e7fb46c 100755
--- a/tools/matchcompiler.py
+++ b/tools/matchcompiler.py
@@ -148,7 +148,7 @@ class MatchCompiler:
             gotoNextToken = '    tok = tok->next();\n'
 
             # if varid is provided, check that it's non-zero on first use
-            if varid and tok.find('%varid%') != -1 and checked_varid is False:
+            if varid and '%varid%' in tok and not checked_varid:
                 ret += '    if (varid==0U)\n'
                 ret += '        throw InternalError(tok, "Internal error. Token::Match called with varid 0. ' +\
                     'Please report this to Cppcheck developers");\n'
@@ -160,7 +160,7 @@ class MatchCompiler:
                 ret += '        ' + returnStatement
 
             # a|b|c
-            elif tok.find('|') > 0:
+            elif '|' in tok:
                 tokens2 = tok.split('|')
                 logicalOp = ' || '
                 if "" in tokens2:
@@ -537,7 +537,7 @@ class MatchCompiler:
 
             # Check for varId
             varId = None
-            if not is_findsimplematch and g0.find("%varid%") != -1:
+            if not is_findsimplematch and "%varid%" in g0:
                 if len(res) == 5:
                     varId = res[4]
                 else:
diff --git a/tools/parse-glibc.py b/tools/parse-glibc.py
index fdefbc8c3..cb79edec8 100644
--- a/tools/parse-glibc.py
+++ b/tools/parse-glibc.py
@@ -19,9 +19,9 @@ def checknonnull(cfg, functionName, nonnull):
             continue
         argpos2 = functionCfg.find('</arg>', argpos1)
         notnullpos = functionCfg.find('not-null', argpos1)
-        if notnullpos > 0 and notnullpos < argpos2:
+        if 0 <= notnullpos < argpos2:
             if s:
-                s = s + ', ' + str(argnr)
+                s += ', ' + str(argnr)
             else:
                 s = str(argnr)
     if s != nonnull:
@@ -102,7 +102,7 @@ def parseheader(cppcheckpath, filename):
         nonnull = None
 
         nonnullStart = line.find('__nonnull')
-        if nonnullStart > 0:
+        if nonnullStart >= 0:
             nonnullStart += 9
             while nonnullStart < len(line) and line[nonnullStart] == ' ':
                 nonnullStart += 1
diff --git a/tools/reduce.py b/tools/reduce.py
index 32da0d1f9..b81b3a82a 100644
--- a/tools/reduce.py
+++ b/tools/reduce.py
@@ -46,7 +46,7 @@ def runtool():
             return True
     elif p.returncode == 0:
         out = comm[0] + '\n' + comm[1]
-        if ('error:' not in out) and (out.find(EXPECTED) > 0):
+        if 'error:' not in out and EXPECTED in out:
             return True
     return False
 
@@ -223,7 +223,7 @@ def removeline(filedata):
         if stmt and strippedline[-1] == ';' and checkpar(line) and '{' not in line and '}' not in line:
             replaceandrun('remove line', filedata, i, '')
 
-        elif stmt and strippedline.find('{') > 0 and strippedline.find('}') == len(strippedline) - 1:
+        elif stmt and '{' in strippedline and strippedline.find('}') == len(strippedline) - 1:
             replaceandrun('remove line', filedata, i, '')
 
         if strippedline[-1] in ';{}':
diff --git a/triage/triage-report.py b/triage/triage-report.py
index 7a9dbebf7..cb7721221 100644
--- a/triage/triage-report.py
+++ b/triage/triage-report.py
@@ -71,7 +71,7 @@ for result in results.split('\n'):
 f = open(project + '/true-positives.txt', 'rt')
 for line in f.readlines():
     line = line.strip()
-    if line.find('] -> [') > 0 or '(error)' not in line:
+    if '] -> [' in line or '(error)' not in line:
         continue
 
     res = re.match('\\[(' + project + '.+):([0-9]+)\\]:\s+[(][a-z]+[)] (.+)', line)
@@ -101,7 +101,7 @@ for line in f.readlines():
 f.close()
 
 project2 = ''
-if project.find('-') > 0:
+if '-' in project:
     project2 = project[:project.find('-')]
 else:
     project2 = project